message list: Cut out now-vestigial MessageList explicit component.
message list: Cut out now-vestigial MessageList explicit component.

This explicit component is now a completely no-op wrapper around
MessageListWeb; so replace it with the latter.  In the next commit
we'll fold the Redux (and action-sheet) `connect` logic below into the
child component's source file.

vishwesh3/zulip-mobile,vishwesh3/zulip-mobile,vishwesh3/zulip-mobile,vishwesh3/zulip-mobile