Membership refactor

Introduce deactivate, membership services

Move membership and user deactivation functions from api crate into those services

src/service/mod.rs

@@ -11,11 +11,13 @@ pub mod admin;
 pub mod appservice;
 pub mod client;
 pub mod config;
+pub mod deactivate;
 pub mod emergency;
 pub mod federation;
 pub mod globals;
 pub mod key_backups;
 pub mod media;
+pub mod membership;
 pub mod presence;
 pub mod pusher;
 pub mod resolver;