Fleshmind - Attempt 3 (#4914)

## About This Pull Request
Brought back based off of
https://github.com/Bubberstation/Bubberstation/pull/2007, made
functional again by myself.
Original Code: https://github.com/Skyrat-SS13/Skyrat-tg/pull/14023

Fleshmind is a PVE event that incorporates some PVP elements in the
later stages of its growth. You defeat it by destroying all its
processors. It has six stages of growth with each stage expanding on its
abilities and the structures and mobs it can deploy. It will announce to
the entire station each time it gains a level or loses a level. Each
level means it has a new processor.

- **Level 1:** The start when it spawns in. It will spawn some basic
structures.
- **Level 2:** It will begin to spawn screamers and whisperers
- **Level 3:** The wireweed is much more situated, and this is the point
where it spawns a very dangerous mech. This is the point where it
becomes very critical. It also starts to spawn Babblers (structures that
spew propaganda into comms) and Modulators. (Gives you hallucinations)
- **Level 4** No new special abilities.
- **Level 5** No new special abilities
- **Level 6** It automatically calls the emergency shuttle to hijack and
spawns a deathsquad on Centcomm. This ends the round.

**Counters:**
- Fight in groups. Carry a melee weapon. (You can still melee the
mechivers and try to kill them before they convert you)
- Wirecutters cut wireweed.
- Ion Weaponry is extremely useful. It also stuns all the mobs.
- Target the processors. If you can pick them off in space, it has
practically zero EVA abilities.
- If someone gets assimilated, should get them to medical if you kill
them.

To run it requires 35 active players and a minimum of an hour to have
passed.
## Why It's Good For The Game
With mold being disabled, there is a missing PVE element in the game,
this fills that niche while also playing around with the idea of
temporary conversion antags in a way that I think works really well.

Wireweed/fleshmind also distracts the crew and security enough to
provide clever antagonists with an opening to commit crimes and get away
with them while the crew has their hands full.

## Proof of Testing
It's been test merged for two months now, it works.
## Changelog
🆑 xPokee, StrangeWeirdKitten, Gandalf2k15
add: New midround event: Fleshmind
/🆑

---------

Co-authored-by: LT3 <83487515+lessthnthree@users.noreply.github.com>
Co-authored-by: Artur Lang <24881678+Arturlang@users.noreply.github.com>
Co-authored-by: Roxy <75404941+TealSeer@users.noreply.github.com>

code/modules/admin/sql_ban_system.dm

@@ -436,6 +436,7 @@
 				ROLE_ASSAULT_OPERATIVE, // SKYRAT EDIT ADDITION
 				ROLE_BLOODSUCKER,// BUBBER EDIT
 				ROLE_VASSAL, // BUBBER EDIT
+				ROLE_WIRE_PRIEST, // BUBBER EDIT
 			),
 			"Skyrat Ban Options" = list(
 				BAN_PACIFICATION,