[PM-15179] Implement add-existing-organization-dialog.component (#13010)

* Implement add-existing-organization-dialog.component

* Add missing button type

* Thomas' feedback

* Import order issue

apps/web/src/locales/en/messages.json

@@ -10346,5 +10346,32 @@
         "example": "10"
       }
     }
+  },
+  "existingOrganization": {
+    "message": "Existing organization"
+  },
+  "selectOrganizationProviderPortal": {
+    "message": "Select an organization to add to your Provider Portal."
+  },
+  "noOrganizations": {
+    "message": "There are no organizations to list"
+  },
+  "yourProviderSubscriptionCredit": {
+    "message": "Your provider subscription will receive a credit for any remaining time in the organization's subscription."
+  },
+  "doYouWantToAddThisOrg": {
+    "message": "Do you want to add this organization to $PROVIDER$?",
+    "placeholders": {
+      "provider": {
+        "content": "$1",
+        "example": "Cool MSP"
+      }
+    }
+  },
+  "addedExistingOrganization": {
+    "message": "Added existing organization"
+  },
+  "assignedExceedsAvailable": {
+    "message": "Assigned seats exceed available seats."
   }
 }