Synth Rank (#8146)

# About the pull request

Gives USCM synths an enlisted rank, this is to highlight who they should
be taking (almost) unquestioned orders from, and who they can freely
ignore where appropriate.

# Explain why it's good for the game

As above


# Testing Photographs and Procedure
<details>
<summary>Screenshots & Videos</summary>

Put screenshots and videos here with an empty line between the
screenshots and the `<details>` tags.

</details>


# Changelog
:cl:
add: USCM Synthetics now have an enlisted rank. (Master Sergeant and
Master Gunnery Sergeant)
/:cl:

Co-authored-by: forest2001 <[email protected]>

code/modules/gear_presets/synths.dm

@@ -60,6 +60,7 @@
 	role_comm_title = "Syn"
 
 	minimap_icon = "synth"
+	paygrades = list(PAY_SHORT_ME8 = JOB_PLAYTIME_TIER_0)
 
 /datum/equipment_preset/synth/uscm/load_gear(mob/living/carbon/human/new_human)
 	var/back_item = /obj/item/storage/backpack/marine/satchel
@@ -83,6 +84,7 @@
 	assignment = JOB_SYNTH
 	rank = "Synthetic"
 	role_comm_title = "Syn"
+	paygrades = list(PAY_SHORT_ME9 = JOB_PLAYTIME_TIER_0)
 
 /datum/equipment_preset/synth/uscm/councillor/load_gear(mob/living/carbon/human/new_human)
 	var/back_item = /obj/item/storage/backpack/satchel
@@ -101,6 +103,7 @@
 /datum/equipment_preset/synth/uscm/wo
 	name = "WO Support Synthetic"
 	flags = EQUIPMENT_PRESET_START_OF_ROUND_WO
+	paygrades = list(PAY_SHORT_ME8 = JOB_PLAYTIME_TIER_0)
 
 /datum/equipment_preset/synth/uscm/wo/load_gear(mob/living/carbon/human/new_human)