Move unittest check to GitHub Actions

[zasdfgbnm]

Tests are parallelized, which significantly reduces the latency for waiting these tests. Azure pipelines are now only used to deploy for now.

[zasdfgbnm]

Hi @farhadrgh, I moved almost all CI checks to GitHub Actions because it is easier to manage. And more importantly, the unit test is now parallelized and should be faster to run. Due to this change, I have to temporarily disable most branch protections. So for this week only, all admins could merge things without passing these checks. So be careful.

[zasdfgbnm]

Please review this, make sure all tests are covered at matrix.test-filenames and if correct, merge. (I merged all other changes without reviewing, because they are more trivial, less important, and reviewing is not convenient in changing the whole CI structure)

[zasdfgbnm]

Also in the future, if new test files are added, remember to update the workflow

[zasdfgbnm]

Also, after this gets merged, we should start splitting larger tests into different files, so that we can run them in parallel to reduce the latency.

[farhadrgh]

LGTM