PM-23851 False requirement to pop out extension when using send files (#17950)

* follow existing popout guard pattern to force popout on firefox when filepicker is exposed

* move firefox guard to tools ownership & revert changes to auth owned file

* initial refactor to consolidate logic  using file-picker-popout.guard

* remove safari from guard & disable forced popout in vault import

* enforce popout on Safari with test coverage

* use userAgent and consistent detection for platform detection

* refactor guard tests involving routes

* replace imports lost during merge

* remove text sends from popout requirement and update tests

* add tooltip and screen-reader text describing popout behavior

libs/tools/send/send-ui/src/new-send-dropdown/new-send-dropdown.component.html

@@ -7,11 +7,13 @@
     <i class="bwi bwi-file-text" slot="start" aria-hidden="true"></i>
     {{ "sendTypeText" | i18n }}
   </a>
-  <a bitMenuItem (click)="sendFileClick()">
+  <a bitMenuItem (click)="sendFileClick()" [title]="'popOutNewWindow' | i18n">
     <div class="tw-flex tw-items-center tw-gap-2">
       <i class="bwi bwi-file" slot="start" aria-hidden="true"></i>
       {{ "sendTypeFile" | i18n }}
       <app-premium-badge></app-premium-badge>
     </div>
+    <span class="tw-sr-only">{{ "popOutNewWindow" | i18n }}</span>
+    <i class="bwi bwi-popout tw-text-muted" slot="end" aria-hidden="true"></i>
   </a>
 </bit-menu>