Add new `mila login` command #751

Job	Run time
Run linting/pre-commit checks	44s
unit-tests (ubuntu-latest, 3.8)	1m 42s
unit-tests (ubuntu-latest, 3.9)	1m 30s
unit-tests (ubuntu-latest, 3.10)	1m 32s
unit-tests (ubuntu-latest, 3.11)	1m 49s
unit-tests (windows-latest, 3.8)	1s
unit-tests (windows-latest, 3.9)	1s
unit-tests (windows-latest, 3.10)	1s
unit-tests (windows-latest, 3.11)	1s
unit-tests (macos-latest, 3.8)	1s
unit-tests (macos-latest, 3.9)	1s
unit-tests (macos-latest, 3.10)	1s
unit-tests (macos-latest, 3.11)	1s
integration tests with a mock slurm cluster	0s
integration tests with a real SLURM cluster	0s
Upload coverage reports to Codecov	0s
	7m 25s

Provide feedback