Allow for setting a editor background image

[v3ss0n]

Currently we need hacks and workarounds just to make a simple feature work : Setting Background Images.

This is what i could do 7 years ago in ATOM editor : Could add background with translucency and CSS text effect.
https://github.com/v3ss0n/steam-pirate-ui

I understand that enabling full CSS features could be performance problem , so what i am requesting is only following features.

• A Proper API to set Background
• Optional Translucency/Tinting support
• Optional Blurring support

It was requested here : #84120
but shot down : #84120 (comment)

How does that increase productivity? I find it unlikely that we would allow this, but maybe there is a good argument to do it.

This is not just for "Looking Good' as It have a lot of productivity use cases and could make a lot of useful extensions that:

• Cheatsheets as Background Images , changes depending on programming languge/framework
• Charts / Graphs / {Stock,Crypto} Prices / Process Monitors Dynamically updated at the back ground.
• Motivational / Quotes chaning every set hours.

This is some of very few usecases that is not just for looks but

[bpasero]

/duplicate #112192

[darren4321]

+1 this request - adjustable transparency and blur