[core] Running scripts for grid and pickers separately

[cherniavskii]

The problem

Currently, scripts like yarn typescript, yarn test:karma and yarn test:unit (it's an open list) run through all the packages in mui-x repo.
However in development, it doesn't make sense to run pickers tests while working on data grid and the other way around.

The goal

To have separate commands or an easy way to narrow down the scope of those scripts, similar to cli.js in material-ui repo:

• for yarn test:unit: we can use an existing cli.js script that's currently not being used: https://github.com/mui/mui-x/blob/ebb0e3b1a4d940b02ca20abd61ade86fce9b6e94/test/cli.js
• for yarn test:karma: we can reuse file pattern logic from cli.js and use it in https://github.com/mui/mui-x/blob/ebb0e3b1a4d940b02ca20abd61ade86fce9b6e94/test/karma.tests.js
• for yarn typescript: we can use lerna run --scope option:
  • yarn typescript --scope "@mui/x-date-*" for date pickers
  • yarn typescript --scope "@mui/x-data-*" for data grid