Allow forcing WebGPU/WebGL on the web player, new command line argument to force graphics backend

[Wumpf]

What

• Fixes Add a way to force WebGPU / WebGL #4898

Bunch of related things that go in here:

• url parameter to force webgl/webgpu: &renderer=webgpu or &renderer=webgl
• command line argument with similar syntax, can be used both for web player and native e.g. --renderer gl, --web-viewer --renderer webgpu
• show webgpu/webgl url on crash
• ui action for reloading webpage with webgpu or webl
• updated trouble shooting docs on

Parsing of backend is actually fairly fuzzy but in docs I stick with wgpu names. Front facing we talk usually about "renderer" but internally we're more correct and call it "wgpu backend" which requires knowing a bit more about how things work.

webgpuwebglswitch.mp4

Screen on crash:

Checklist

• I have read and agree to Contributor Guide and the Code of Conduct
• I've included a screenshot or gif (if applicable)
• I have tested the web demo (if applicable):
  • Using newly built examples: app.rerun.io
  • Using examples from latest main build: app.rerun.io
  • Using full set of examples from nightly build: app.rerun.io
• The PR title and labels are set such as to maximize their usefulness for the next release's CHANGELOG

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[emilk]

• url parameter to force webgl/webgpu: &renderer=webgpu or &renderer=webgl
• command line argument with similar syntax, can be used both for web player and native e.g. --force-renderer gl, --web-viewer --force-renderer webgpu

Let's be consistent, and use --renderer

[Wumpf]

done, it's --renderer now