Refactor test code to go under a single 'test' folder

[rchiodo]

As discussed in our architecture review, this task is to move 'test' related code into a 'test' folder (or whatever you decided to name it).

The main reason for this is to ensure we never reference test related code inside of production code. One way to achieve this is to have a completely separate 'test' folder at the root (instead of under src).

This would include stuff like:

• standardTest.ts
• index.ts
• all *.vscode.test.ts files
• test helper code

It would NOT include:

• all unit tests. These would reside next to the code they're testing

[DonJayamanne]

One way to achieve this is to have a completely separate 'test' folder at the root (instead of under src).

Not moving all of the tests, no need we can use linters to achieve the same requirement.

[rchiodo]

Not moving all of the tests, no need we can use linters to achieve the same requirement.

Yeah I tried this and it was a huge pain having two root dirs in the tsconfig. Changed relative paths everywhere.

[DonJayamanne]

Done as per discussion (basically do not move anything, added linters to ensure extension code cannot consume test code)