Update logic via --lint option

[jonhealy1]

The --lint option currently displays the same output as stac-check does in default mode. This creates a situation now where stac-validator is calling the stac-check that uses stac-validator to display validation information. Stac-validator should only call the linting logic from stac-lint and append any linting information to the validation messages presently used in stac-validator. Validation then remains within stac-validator.