Add max depth for searching for roku projects

[TwitchBronBron]

Add a max depth of 15 when searching the workspace for roku projects. That way it prevents infinite loops, and if devs have folder sthat far down, there's probably going to be other issues.

I believe this work should probably be done in ProjectManager.ts in the locations where we call fastGlob.

Requirements:

• add a max depth of 15
• make the depth configurable in the brightscript.languageServer. settings
• add unit tests to verify it's stopping at the specified depth. Test at depth 1, 5, 20, and also that the default is 15