rename api::client_server to api::client

src/admin/room/room_moderation_commands.rs

src/admin/user/user_commands.rs

src/api/client/account.rs

src/api/client/alias.rs

src/api/client/backup.rs

src/api/client/capabilities.rs

src/api/client/config.rs

src/api/client/context.rs

src/api/client/device.rs

src/api/client/directory.rs

src/api/client/filter.rs

src/api/client/keys.rs

src/api/client/media.rs

src/api/client/membership.rs

src/api/client/message.rs

src/api/client/mod.rs

src/api/client/presence.rs

src/api/client/profile.rs

src/api/client/push.rs

src/api/client/read_marker.rs