Make flashlights, atmos hardsuit, and RGB use the new layer features (#6253)

* Make flashlights, atmos hardsuit, and RGB use the new layer features

* avoid self-conflict

* fix rgb not updating on add

* cleanup

* Update Content.Client/Light/RgbLightControllerSystem.cs

Co-authored-by: mirrorcult <lunarautomaton6@gmail.com>

* cleanup diff

Co-authored-by: mirrorcult <lunarautomaton6@gmail.com>

Resources/Textures/Objects/Tools/flashlight.rsi/meta.json

@@ -17,19 +17,19 @@
       "name": "flashlight-overlay"
     },
     {
-      "name": "off-inhand-left",
+      "name": "inhand-left",
       "directions": 4
     },
     {
-      "name": "off-inhand-right",
+      "name": "inhand-right",
       "directions": 4
     },
     {
-      "name": "on-inhand-left",
+      "name": "inhand-left-light",
       "directions": 4
     },
     {
-      "name": "on-inhand-right",
+      "name": "inhand-right-light",
       "directions": 4
     },
     {