[Core] Command runner refactor and avoid `source ~/.bashrc` for bette… #14492

Job	Run time
python-test (3.8, tests/unit_tests)	6m 13s
python-test (3.8, tests/test_api.py)	3m 47s
python-test (3.8, tests/test_cli.py)	4m 39s
python-test (3.8, tests/test_config.py)	3m 37s
python-test (3.8, tests/test_global_user_state.py)	3m 38s
python-test (3.8, tests/test_jobs.py)	4m 17s
python-test (3.8, tests/test_list_accelerators.py)	4m 2s
python-test (3.8, tests/test_optimizer_dryruns.py)	5m 24s
python-test (3.8, tests/test_optimizer_random_dag.py)	4m 24s
python-test (3.8, tests/test_storage.py)	3m 37s
python-test (3.8, tests/test_wheels.py)	3m 53s
python-test (3.8, tests/test_jobs_and_serve.py)	3m 40s
python-test (3.8, tests/test_yaml_parser.py)	3m 38s
	54m 49s

Provide feedback