Added chat window transparency slider to options (#24990)

* Adds a new slider to the misc tab in options that lets the player set chat window transparency

* Tweaked variable names

* Fixed order to match UI

* Renamed set chat window transparency function

* Changed and refactored to opacity instead of transparency

* Remove unnecessary int to float conversions

Slider used to be 0-100 while the CCVar was 0.0-1.0f. This is confusing and was only used for rounding to 2 decimal points.

* Round the value to two decimal points

* Remove rounding for now

* Rename

* Unhardcode chat color by moving to stylesheet

* Fix indent

* Make opacity slider only change opacity

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Co-authored-by: Your Name <you@example.com>
Co-authored-by: ShadowCommander <10494922+ShadowCommander@users.noreply.github.com>

Resources/Locale/en-US/escape-menu/ui/options-menu.ftl

@@ -48,6 +48,8 @@ ui-options-fancy-name-background = Add background to speech bubble names
 ui-options-enable-color-name = Add colors to character names
 ui-options-colorblind-friendly = Colorblind friendly mode
 ui-options-reduced-motion = Reduce motion of visual effects
+ui-options-chat-window-opacity = Chat window opacity
+ui-options-chat-window-opacity-percent = { TOSTRING($opacity, "P0") }
 ui-options-screen-shake-intensity = Screen shake intensity
 ui-options-screen-shake-percent = { TOSTRING($intensity, "P0") }
 ui-options-vsync = VSync