Remove flutter chat (#26)

Had to squash merge manually as Forgejo was erroring

lib/widgets/renderers/membership.dart

@@ -0,0 +1,57 @@
+import "package:flutter/material.dart";
+import "package:nexus/helpers/extensions/get_localpart.dart";
+import "package:nexus/helpers/extensions/show_user_popover.dart";
+import "package:nexus/helpers/extensions/string_to_color.dart";
+import "package:nexus/models/content/membership.dart";
+import "package:nexus/models/event.dart";
+import "package:nexus/models/membership_status.dart";
+import "package:nexus/widgets/lazy_loading/message_displayname.dart";
+import "package:nexus/widgets/renderers/generic_event.dart";
+
+class MembershipRenderer extends StatelessWidget {
+  final Event event;
+  const MembershipRenderer(this.event, {super.key});
+
+  @override
+  Widget build(BuildContext context) {
+    assert(
+      event.content is MembershipContent,
+      "Make sure to only pass membership events to MembershipRenderer",
+    );
+
+    return switch (event.content) {
+      MembershipContent content => GenericEventRenderer(Icons.people, [
+        InkWell(
+          onTapUp: (details) => context.showUserPopover(
+            content,
+            event.stateKey!,
+            globalPosition: details.globalPosition,
+          ),
+          child: Text(
+            overflow: TextOverflow.ellipsis,
+            content.displayName ?? event.stateKey!.localpart,
+            maxLines: 1,
+            style: TextStyle(
+              color: event.sender.colorHash,
+              fontWeight: FontWeight.bold,
+            ),
+          ),
+        ),
+        Text(
+          overflow: TextOverflow.ellipsis,
+          maxLines: 1,
+          "${switch (content.status) {
+            MembershipStatus.invite => "was invited to",
+            MembershipStatus.join => "joined",
+            MembershipStatus.leave => event.sender == event.stateKey ? "left" : (event.unsigned["prev_content"]?["membership"] == "ban" ? "was unbanned from" : "was kicked from"),
+            MembershipStatus.ban => "was banned from",
+            MembershipStatus.knock => "asked to join",
+          }} the room${event.sender == event.stateKey ? "" : " by "}",
+        ),
+        if (event.sender != event.stateKey) MessageDisplayname(event),
+        if (content.reason != null) Text("for \"${content.reason}\""),
+      ]),
+      _ => SizedBox.shrink(),
+    };
+  }
+}