Add Continuous Integration

[Speykious]

Closes #3.

Things have never worked so well before.

• [x] Generate C# protobuf sources
• [x] Build libmediapipe_c on workflow dispatch
  • [x] Windows
  • [x] Linux (CPU)
  • [x] Linux (GPU)
  • [x] MacOS
• [x] Deploy Nuget packages on pre-/release
  • [x] Mediapipe.Net.Framework.Protobuf
  • [x] Mediapipe.Net.Runtime.CPU
  • [x] Mediapipe.Net.Runtime.GPU
• [x] Good release text

  • [ ] Deploy packages to GitHub (we can deal with that in a future separate PR)
  • [ ] Deploy packages to Nuget (waiting for a Vignette Microsoft account)

[adryzz]

time to drop MacOS suppor

[Speykious]

I mean, here it's not about platforms we as Vignette can code on, since this is just about compiling the native library which is available for all 3 operating systems. How we've been able to separate the runtime from the bindings would have allowed us to do so... We just don't have that budget yet. :/

[Speykious]

Turns out that this budget doesn't matter if the repo is public! Very well, making it public was our intention from the beginning anyways.

[Speykious]

Niget