Add user search for dm chats (#739)

* Add searchUsers in ClientProxy

* Add UserSearchProtocol

* Delete UserSearch file

* Add search

* Refine StartChatScreen

* Improve StartChatViewModel

* Add localizations

* Fix no result style

* Update localizations

* Add UTs

* Add UI tests

* Cleanup

* Refine tests

* Add changelog.d file

* Naming refactor

* Refactor ClientProxyProtocol api

* Fix typo

* Add mark

* Rename tests

* Update Dangerfile

* Improve UI test code

* Refactor search api

* Improve style

* Improve combine chain

* Add comment

* Improve StartChatScreen

* Improve updateState

* Add extension Published.Publisher

* Improve UI tests

* Remove Combine import

* Cleanup

* Remove “proxy” wording

* Delete extra extensions

* Refactor Publisher api

ElementX/Sources/Mocks/UserProfile+Mock.swift

@@ -0,0 +1,32 @@
+//
+// Copyright 2023 New Vector Ltd
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+
+import Foundation
+
+extension UserProfile {
+    // Mocks
+    static var mockAlice: UserProfile {
+        .init(userID: "@alice:matrix.org", displayName: "Alice", avatarURL: URL(staticString: "mxc://matrix.org/UcCimidcvpFvWkPzvjXMQPHA"))
+    }
+
+    static var mockBob: UserProfile {
+        .init(userID: "@bob:matrix.org", displayName: "Bob", avatarURL: nil)
+    }
+
+    static var mockCharlie: UserProfile {
+        .init(userID: "@charlie:matrix.org", displayName: "Charlie", avatarURL: nil)
+    }
+}