Allow extra 3rd party licenses

[sarah-witt]

What does this PR do?

Updates the validate license command to add the ability for integrations to have 3rd party licenses which are not pulled directly from the requirements file and the origin is not PyPI.

Motivation

#9786

Additional Notes

To test, add a LICENSE-3rdparty-extra.csv to the directory of any check. See #9786 for an example.

Review checklist (to be filled by reviewers)

• Feature or bugfix MUST have appropriate tests (unit, integration, e2e)
• PR title must be written as a CHANGELOG entry (see why)
• Files changes must correspond to the primary purpose of the PR as described in the title (small unrelated changes should have their own PR)
• PR must have changelog/ and integration/ labels attached

[codecov]

Codecov Report

Merging #9796 (b0c06d9) into master (f44c7b9) will not change coverage.
The diff coverage is n/a.

Flag	Coverage Δ
datadog_checks_dev	79.93% <ø> (ø)

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[ofek]

Instead, wdyta:

Suggested change

	def get_extra_license_file(check_name):
	path = os.path.join(get_root(), check_name, 'LICENSE-3rdparty-extra.csv')
	return path, file_exists(path)
	def get_extra_license_files():
	for path in os.listdir(get_root()):
	if not file_exists(get_manifest_file(path)):
	continue
	extra_license_file = os.path.join(get_root(), path, 'LICENSE-3rdparty-extra.csv')
	if file_exists(extra_license_file):
	yield extra_license_file

[sarah-witt]

Sounds good- updated!