[Feature]: Light/aura opacity

[bubblobill]

Feature Request

Light and aura opacity are set in client preferences with a one size fits all setting for each. Particularly when stacking auras to achieve a desired effect being limited to solid colours can be limiting.

The Solution you'd like

I would like granular control over aura (and light) opacity by extend the colour definition from 6 digit hex to 8 digit hex. Where 6 digits are provided, treat as normal, where 8 digits are provided, multiply opacity. ` Normal aura Aura red: aura circle 2.5#ff0000

Extra see-through aura Aura red: aura circle 2.5#ff00001a`

Alternatives that you've considered.

No response

Additional Context

No response

[bubblobill]

Related #1108 #646 #1954