Add av-metrics-gui-tool

[Luni-4]

This PR adds av-metrics-gui-tool, an iced GUI tool that computes video metrics.

Since the building is extremely slow due to the great amount of dependencies, for now the tool is not a workspace member, but I'm planning to add a deploy action in a following PR.

The tool also runs on web too thanks to the WebAssembly support provided by iced, but it needs more in depth tests.

Thanks in advance for your review!

[vibhoothi]

Can you please add some screenshots for quick view^^

[vibhoothi]

This might require a rebase to master

[Luni-4]

@vibhoothi

Yep, I need to fix some stuff and clean up the code a bit, I'm going to work on it as soon as I can

[Luni-4]

@vibhoothi @shssoichiro

We can consider this PR ready. The GUI can compute video metrics on Linux and Windows through FFmpeg, and Y4m also, furthermore we have also added a script to automatically deploy the FFmpeg binaries.

What we were not able to achieve:

• For now, we can create a wasm32 binary but unfortunately the metrics can't be computed since that platform is not supported yet. We need to add the wasm32 platform for the av-metrics crate.
• We can build the macos binary, but we cannot run it because of this winit limitation with sync file dialogs: [MacOS] Dialogues freeze when used in winit event loop rust-windowing/winit#1779. Iced makes use of winit as dependency, so until that bug will not be fixed, we are stuck. Perhaps we could create the main loop ourselves, as done here, but that would complicate a lot the entire code

Here the artifacts produced by the script: https://github.com/Luni-4/av-metrics/actions/runs/1208712639
To run the wasm32 binary and JavaScript bindings, one can use the python3 -m http.server in the artifact's folder and see the result through a browser.

[Luni-4]

@vibhoothi

I tidied up the code a bit, I think we can merge it. You can find the final release here. I will iterate over the MacOS target later.

Wasm-32 can't be run in an easy way because we have a problem with the parallelism provided by rayon, there is a workaround but it doesn't work on any browser as stated here

[vibhoothi]

LGTM to me, apart from one comment