Give both Squad Leader and Assistants the ability to call in Arty/mortar support

[LordDz]

Instead of adding back the Artillery Observer class, we give the assistant the ability to call in arty and make HE/Smoke requests.

This will ease the burden on the squad leader and make mortar operators happier as they will have more marked targets.

[Enfield-303]

Lots of the changes that you are proposing have been talked over before, and have been filed under a future "squad update" in which lots of the layout and functionalities of squad mechanics will be changed, for example, on your previous pull request about logistics roles, there is an idea to create a "logistics squad" instead of having them be intermingled with normal infantry squad layouts

As well as this, artillery and fire support have been talked about previously and one of the main points that had been brought up is bringing back the artillery observer role in order to streamline gameplay for regular infantry squads.

you seem to be doing quite a bit and the tenacity of your PRs are great, if i could offer you my discord tag, that being Enfield#4627 i could reach out and chat to you about it :)