feat(content,mods/fuji_mpp): mainline a few more professions, add combat engineer

[chaosvolt]

Purpose of change

Planned followup to the profession updates I did.

Describe the solution

1. Mainlined the automatic rifleman, grenadier, and designated marksman professions from Fuji's mod.
2. Modernized and cleaned up the starting skills and items of said professions. Point costs set 1 higher than rifleman, descriptions rewritten to be less meme-y, starting skills updated to resemble that of rifleman's starting skillset, basic uniform and misc items consistent with the rifleman, hand grenades in the requisite pouch, automatic rifleman's vest holding mags for their sidearm, M249 assigned an ACOG scope instead of holo sight, marksman's M14 assigned a scope instead of ACOG, automatic rifleman nerfed to only carry 200 rounds of their primary weapon's ammo, etc.
3. Added a combat engineer profession I wrote up. Geared towards having the basics of construction and some relevant entry tools, along with a smattering of utility skills all relevant to building and successfully placing bots (though for balance reasons not enough to autolearn much of that, since is a lot of skills).
4. Removed the injections of mainlined professions from Fuji's mod, adding the new professions to heli crash and overrun in vanilla.
5. Misc: Updated the military pilot profession to actually put their M17 magazines in the leg pouch they start with.

Describe alternatives you've considered

1. Mainlining all the professions from the mod.
2. Putting the combat engineer's C-4 in a grenade pouch?

Testing

1. Checked affected files for syntax and lint errors.
2. Loaded up Fuji's mod to ensure I didn't break anything.
3. Looked at profession loadouts to check that things looked reasonably consistent.

Additional context

Screenshots:

Automatic rifleman:

Grenadier:

Designated marksman:

Engineer:

Checklist