Moving V2 files into separate folder as ground work for deletion/moving to other branch

[Lorthiz]

In this commit I moved all code I could find related to V2 and moved it to related folder.
It's a ground work in preparation for either axing whole V2 version or moving it to a separete branch

1. V1 is totally untouched as much as it needed to be and all the features should work normally.
2. Script to run local version also runs without any problems and is also pinned in package.json
3. V2 folder can be axed at any point and it will not impact V1 in any way - Tested locally

There is a question of few environments/files/testing files:

1. playground.html -> it only loads a preview of some unfinished features related to Yaml edit
2. github_oauth.html -> another testing playfield for github token - most probably related to v2 GithubFileSource
3. serve_files.py, serve_practice.py and checker.js -> those files seems like attempt to load local files with python,
4. tsconfig.playground.json -> used as part of task to build playground.html,

Also the same for the directories:

1. template_compiler -> used by playground.html if that file is to be deleted then this folder also
2. practice -> some random files probably for testing, not used anywhere

@generalmimon What do you think?

[Lorthiz]

Everything is prepared for V2 to be removed. Current branch version, still has V2. V1 and V2 works the same as before my changes.

Steps to remove V2:

1. Remove src/v2 folder
2. Remove file build_v2_related
3. Remove build_v2_related execution from build
4. Remove file v2.html