Add new commands to list installed browsers.
Solves #34183
* Add `playwright ls` command to list installed browsers in `packages/playwright-core/src/cli/commands/ls.ts`.
* Add `--list` option to `npx playwright install` command in `packages/playwright-core/src/cli/commands/install.ts`.
* Register the new `ls` command in the CLI program in `packages/playwright-core/src/cli/program.ts`.
* Write tests for the `playwright ls` command in `packages/playwright-core/src/cli/commands/ls.test.ts`.
* Add documentation for the new `playwright ls` command and `--list` option in `docs/src/cli.md`.
* Update `.github/actions/run-test/action.yml` to use `npx playwright install --with-deps --list` to list installed browsers.
