Invite users to existing rooms (#441)

Invite users to existing rooms

Scope:

- Allow inviting from the room detail screen and the member list
- Invite option is only shown if the user has the correct power level
- Search flow the same as creating a new room, allowing multi-select
- Existing room members/invitees are disabled with a custom caption
- Sending is asynchronous, an error dialog will appear wherever the
  user is if necessary

Closes #245

libraries/matrix/test/src/main/kotlin/io/element/android/libraries/matrix/test/room/FakeMatrixRoom.kt

@@ -59,6 +59,8 @@ class FakeMatrixRoom(
     private var updateMembersResult: Result<Unit> = Result.success(Unit)
     private var acceptInviteResult = Result.success(Unit)
     private var rejectInviteResult = Result.success(Unit)
+    private var inviteUserResult = Result.success(Unit)
+    private var canInviteResult = Result.success(true)
     private var sendMediaResult = Result.success(Unit)
     var sendMediaCount = 0
         private set
@@ -69,6 +71,9 @@ class FakeMatrixRoom(
     var isInviteRejected: Boolean = false
         private set
 
+    var invitedUserId: UserId? = null
+        private set
+
     private var leaveRoomError: Throwable? = null
 
     override val membersStateFlow: MutableStateFlow<MatrixRoomMembersState> = MutableStateFlow(MatrixRoomMembersState.Unknown)
@@ -136,6 +141,15 @@ class FakeMatrixRoom(
         return rejectInviteResult
     }
 
+    override suspend fun inviteUserById(id: UserId): Result<Unit> {
+        invitedUserId = id
+        return inviteUserResult
+    }
+
+    override suspend fun canInvite(): Result<Boolean> {
+        return canInviteResult
+    }
+
     override suspend fun sendImage(file: File, thumbnailFile: File, imageInfo: ImageInfo): Result<Unit> = sendMediaResult.also { sendMediaCount++ }
 
     override suspend fun sendVideo(file: File, thumbnailFile: File, videoInfo: VideoInfo): Result<Unit> = sendMediaResult.also { sendMediaCount++ }
@@ -174,6 +188,14 @@ class FakeMatrixRoom(
         rejectInviteResult = result
     }
 
+    fun givenInviteUserResult(result: Result<Unit>) {
+        inviteUserResult = result
+    }
+
+    fun givenCanInviteResult(result: Result<Boolean>) {
+        canInviteResult = result
+    }
+
     fun givenIgnoreResult(result: Result<Unit>) {
         ignoreResult = result
     }