feat: Better invite search bar

lib/views/chat_list.dart

@@ -272,6 +272,7 @@ class _ChatListState extends State<ChatList> {
                             ? Text(_selectedRoomIds.length.toString())
                             : DefaultAppBarSearchField(
                                 searchController: searchController,
+                                hintText: L10n.of(context).searchForAChat,
                                 onChanged: (_) => setState(() => null),
                               ),
                   ),

lib/views/discover_view.dart

@@ -146,6 +146,7 @@ class _DiscoverPageState extends State<DiscoverPage> {
         elevation: _scrolledToTop ? 0 : null,
         title: DefaultAppBarSearchField(
           onChanged: (text) => _search(context, text),
+          hintText: L10n.of(context).searchForAChat,
           suffix: IconButton(
             icon: Icon(Icons.edit_outlined),
             onPressed: () => _setServer(context),

lib/views/invitation_selection.dart

@@ -1,5 +1,6 @@
 import 'dart:async';
 
+import 'package:fluffychat/components/default_app_bar_search_field.dart';
 import 'package:flushbar/flushbar_helper.dart';
 import 'package:famedlysdk/famedlysdk.dart';
 import 'package:famedlysdk/matrix_api.dart';
@@ -120,35 +121,11 @@ class _InvitationSelectionState extends State<InvitationSelection> {
       firstScaffold: ChatList(activeChat: widget.room.id),
       secondScaffold: Scaffold(
           appBar: AppBar(
-            title: Text(L10n.of(context).inviteContact),
-            bottom: PreferredSize(
-              preferredSize: Size.fromHeight(92),
-              child: Padding(
-                padding: const EdgeInsets.all(16.0),
-                child: TextField(
-                  controller: controller,
-                  autofocus: true,
-                  autocorrect: false,
-                  textInputAction: TextInputAction.search,
-                  onChanged: (String text) =>
-                      searchUserWithCoolDown(context, text),
-                  onSubmitted: (String text) => searchUser(context, text),
-                  decoration: InputDecoration(
-                    border: OutlineInputBorder(),
-                    prefixText: '@',
-                    hintText: L10n.of(context).username,
-                    labelText: L10n.of(context).inviteContactToGroup(groupName),
-                    suffixIcon: loading
-                        ? Container(
-                            padding: const EdgeInsets.all(8.0),
-                            width: 12,
-                            height: 12,
-                            child: CircularProgressIndicator(),
-                          )
-                        : Icon(Icons.search_outlined),
-                  ),
-                ),
-              ),
+            titleSpacing: 0,
+            title: DefaultAppBarSearchField(
+              autofocus: true,
+              hintText: L10n.of(context).inviteContactToGroup(groupName),
+              onChanged: (String text) => searchUserWithCoolDown(context, text),
             ),
           ),
           body: foundProfiles.isNotEmpty