[PM-15637] Add Email Notification Templates and Logic for Device Approval Requests (#5270)

* Add device approval notification email templates

* Add DeviceApprovalRequestedViewModel for device approval notifications

* Add method to send device approval requested notification email

* Send email notification to Organization Admins when adding a new admin approval auth request

* Add tests for device approval notification email sending in AuthRequestServiceTests

* fix(email-templates): Remove unnecessary triple braces from user name variable in device approval notification emails

* Add feature flag for admin notifications on device approval requests

* Add logging for skipped admin notifications on device approval requests

src/Core/MailTemplates/Handlebars/AdminConsole/NotifyAdminDeviceApprovalRequested.html.hbs

@@ -0,0 +1,23 @@
+{{#>FullHtmlLayout}}
+<table width="100%" cellpadding="0" cellspacing="0"
+    style="margin: 0; box-sizing: border-box; ">
+    <tr
+        style="margin: 0; box-sizing: border-box; ">
+        <td class="content-block last"
+            style="font-family: 'Helvetica Neue', Helvetica, Arial, sans-serif; box-sizing: border-box; font-size: 16px; color: #333; line-height: 25px; margin: 0; -webkit-font-smoothing: antialiased; padding: 0 0 10px; -webkit-text-size-adjust: none;"
+            valign="top">
+            {{UserNameRequestingAccess}} has sent a device approval request. Review login requests to allow the member to finish logging in.
+            <br class="line-break" />
+            <br class="line-break" />
+        </td>
+    </tr>
+    <tr style="margin: 0; box-sizing: border-box; color: #333; line-height: 25px; -webkit-font-smoothing: antialiased; -webkit-text-size-adjust: none;">
+        <td class="content-block" style="font-family: 'Helvetica Neue', Helvetica, Arial, sans-serif; box-sizing: border-box; font-size: 16px; color: #333; line-height: 25px; margin: 0; -webkit-font-smoothing: antialiased; padding: 0 0 10px; -webkit-text-size-adjust: none; text-align: center;" valign="top" align="center">
+            <a href="{{Url}}" clicktracking=off target="_blank" rel="noopener noreferrer" style="color: #ffffff; text-decoration: none; text-align: center; cursor: pointer; display: inline-block; border-radius: 5px; background-color: #175DDC; border-color: #175DDC; border-style: solid; border-width: 10px 20px; margin: 0; font-family: 'Helvetica Neue', Helvetica, Arial, sans-serif; box-sizing: border-box; font-size: 16px; line-height: 25px; -webkit-font-smoothing: antialiased; -webkit-text-size-adjust: none;">
+                Review request
+            </a>
+            <br class="line-break" />
+        </td>
+    </tr>
+</table>
+{{/FullHtmlLayout}}

src/Core/MailTemplates/Handlebars/AdminConsole/NotifyAdminDeviceApprovalRequested.text.hbs

@@ -0,0 +1,5 @@
+{{#>BasicTextLayout}}
+{{UserNameRequestingAccess}} has sent a device approval request. Review login requests to allow the member to finish logging in.
+
+{{Url}}
+{{/BasicTextLayout}}

src/Core/MailTemplates/Handlebars/AdminConsole/SelfHostNotifyAdminDeviceApprovalRequested.html.hbs

@@ -0,0 +1,29 @@
+{{#>FullHtmlLayout}}
+<table width="100%" cellpadding="0" cellspacing="0"
+    style="margin: 0; box-sizing: border-box; ">
+    <tr style="margin: 0; box-sizing: border-box; ">
+        <td class="content-block last"
+            style="font-family: 'Helvetica Neue', Helvetica, Arial, sans-serif; box-sizing: border-box; font-size: 16px; color: #333; line-height: 25px; margin: 0; -webkit-font-smoothing: antialiased; padding: 0 0 10px; -webkit-text-size-adjust: none;"
+            valign="top">
+            {{UserNameRequestingAccess}} has sent a device approval request. Review login requests to allow the member to finish logging in.
+        </td>
+    </tr>
+    <tr style="margin: 0; box-sizing: border-box; ">
+        <td class="content-block last"
+            style="font-family: 'Helvetica Neue', Helvetica, Arial, sans-serif; box-sizing: border-box; font-size: 16px; color: #333; line-height: 25px; margin: 0; -webkit-font-smoothing: antialiased; padding: 0 0 10px; -webkit-text-size-adjust: none;"
+            valign="top">
+            To review requests, log in to your self-hosted instance → navigate to the Admin Console → select Device Approvals
+            <br class="line-break" />
+            <br class="line-break" />
+        </td>
+    </tr>
+    <tr style="margin: 0; box-sizing: border-box; color: #333; line-height: 25px; -webkit-font-smoothing: antialiased; -webkit-text-size-adjust: none;">
+        <td class="content-block" style="font-family: 'Helvetica Neue', Helvetica, Arial, sans-serif; box-sizing: border-box; font-size: 16px; color: #333; line-height: 25px; margin: 0; -webkit-font-smoothing: antialiased; padding: 0 0 10px; -webkit-text-size-adjust: none; text-align: center;" valign="top" align="center">
+            <a href="{{Url}}" clicktracking=off target="_blank" rel="noopener noreferrer" style="color: #ffffff; text-decoration: none; text-align: center; cursor: pointer; display: inline-block; border-radius: 5px; background-color: #175DDC; border-color: #175DDC; border-style: solid; border-width: 10px 20px; margin: 0; font-family: 'Helvetica Neue', Helvetica, Arial, sans-serif; box-sizing: border-box; font-size: 16px; line-height: 25px; -webkit-font-smoothing: antialiased; -webkit-text-size-adjust: none;">
+                Review request
+            </a>
+            <br class="line-break" />
+        </td>
+    </tr>
+</table>
+{{/FullHtmlLayout}}

src/Core/MailTemplates/Handlebars/AdminConsole/SelfHostNotifyAdminDeviceApprovalRequested.text.hbs

@@ -0,0 +1,7 @@
+{{#>BasicTextLayout}}
+{{UserNameRequestingAccess}} has sent a device approval request. Review login requests to allow the member to finish logging in.
+
+To review requests, log in to your self-hosted instance -> navigate to the Admin Console -> select Device Approvals.
+
+{{Url}}
+{{/BasicTextLayout}}