Member avatars without canvas (#9990)

* Strict typechecking fixes for Base/Member/Avatar

Update the core avatar files to pass `--strict --noImplicitAny` typechecks.

Signed-off-by: Clark Fischer <clark.fischer@gmail.com>

* Add tests for Base/Member/Avatar

More thoroughly test the core avatar files. Not necessarily the most thorough,
but an improvement.

Signed-off-by: Clark Fischer <clark.fischer@gmail.com>

* Extract TextAvatar from BaseAvatar

Extracted the fallback/textual avatar into its own component.

Signed-off-by: Clark Fischer <clark.fischer@gmail.com>

* Use standard HTML for non-image avatars

Firefox users with `resistFingerprinting` enabled were seeing random noise
for rooms and users without avatars. There's no real reason to use data
URLs to present flat colors.

This converts non-image avatars to inline blocks with background colors.

See https://github.com/vector-im/element-web/issues/23936

Signed-off-by: Clark Fischer <clark.fischer@gmail.com>

* Have pills use solid backgrounds rather than colored images

Similar to room and member avatars, pills now use colored pseudo-elements
rather than background images.

Signed-off-by: Clark Fischer <clark.fischer@gmail.com>

---------

Signed-off-by: Clark Fischer <clark.fischer@gmail.com>
Co-authored-by: Andy Balaam <andy.balaam@matrix.org>

src/components/views/avatars/RoomAvatar.tsx

@@ -109,7 +109,8 @@ export default class RoomAvatar extends React.Component<IProps, IState> {
     }
 
     private onRoomAvatarClick = (): void => {
-        const avatarUrl = Avatar.avatarUrlForRoom(this.props.room, null, null, null);
+        const avatarMxc = this.props.room?.getMxcAvatarUrl();
+        const avatarUrl = avatarMxc ? mediaFromMxc(avatarMxc).srcHttp : null;
         const params = {
             src: avatarUrl,
             name: this.props.room.name,