Test: task discovery

[dbaeumer]

Tests: #28235

• macOS - @joaomoreno
• any os - @michelkaporin

Clone some GitHub repositories that use typescript, npm or gulp and test how tasks are discovered. Examples to clone are:

• https://github.com/Microsoft/vscode-languageserver-node: if you use that open he jsonrpc sub folder
  delete the tasks.json file and test task discovery
• https://github.com/AngularClass/angular-starter.git

While testing it trigger all actions from the menu instead of the Command Palette