rebase Experimental/webgl branch to latest version

[Thaina]

As it seem webgl branch was staled and very outdated, I try to bring webgl branch closer to newest version and so I could continued trying to make this library work with webgl

Have various place patching with NotImplementedException and some native methods are not really compatible, but currently seem like there was no error. And the windows platform are still pass all the tests

[karasusan]

Thanks for your contribution! I see that there are some conflicts for this PR, can you confirm?

[Thaina]

Thanks for your contribution! I see that there are some conflicts for this PR, can you confirm?

I am not sure why because it not conflict in my machine

Although it might be because I am rebase and fix everything before commit, instead of merge. So it conflict with the current branch because it like I have remade the whole latest commit of that branch, and it try to override on the pull request

[karasusan]

@Thaina I can't merge it because of the conflict, so I would like to make a new branch instead of this old branch. What do you think about it?

[Thaina]

If that would work then I am very fine

[karasusan]

Added the branch here https://github.com/Unity-Technologies/com.unity.webrtc/tree/thaina/experimental/webgl-platform

[karasusan]

I am closing this PR because I made the new branch to store these change.