Platoons social functionality (#91)

### Description

This implements and completes #87 (to the best of my knowledge)

### Game

Robocraft

### Please confirm

- [x] I am the legal owner or represent the owner of all work submitted
- [x] I consent to my submission being added to this FOSS project
- [ ] This PR used LLMs to generate some or all of the code changes

Reviewed-on: https://git.ngram.ca/OpenJam/rc-servers/pulls/91
Co-authored-by: NG (Graham) <ngniusness@gmail.com>
Co-committed-by: NG (Graham) <ngniusness@gmail.com>

rc_social_room/src/operations/clan_invite.rs

@@ -10,6 +10,7 @@ pub(super) fn clan_invites_provider<C: Send + Sync>() -> SimpleFunc<39, crate::U
         let mut params = params.to_dict();
         params.insert(PARAM_KEY, Typed::<C>::Arr(Arr {
             ty: polariton::serdes::TypePrefix::HashMap, // hashmap
+            custom_ty: None,
             /*items: vec![
                 ClanInviteInfo {
                     username: "RE_user1".to_owned(),