Add sanity rule with check for bad and disallowed ignores

[alisonlhart]

Note: This is an extremely opinionated rule that Partner Engineering enforces for certified content.

New rule sanity checks the tests/sanity/ignore-x.x.txt files for disallowed ignores. Commented-out entries are not evaluated.
Currently (broadly) allowed ignores are:

• validate-modules:missing-gplv3-license
• import-2.6
• import-2.6!skip
• import-2.7
• import-2.7!skip
• import-3.5
• import-3.5!skip
• compile-2.6
• compile-2.6!skip
• compile-2.7
• compile-2.7!skip
• compile-3.5
• compile-3.5!skip

Error breakdown:

• sanity[cannot-ignore] - Ignore file contains a test that is not on the allow list.
• sanity[bad-ignore] - Ignore file entry is formatted incorrectly.

Other changes:

• Added new file type: sanity-ignore-file to recognize files with glob pattern tests/sanity/ignore*.txt
• Updated test count to account for 3 tests in sanity.py
• Added rule under production profile

Fixes: #2121

[alisonlhart]

Note: The validate-modules:missing-gplv3-license entry is throwing a cspell error for gplv.

[thedoubl3j]

looks good and what we want to enforce from a certification stand point.

[ssbarnea]

Eco pipeline is correctly failing as cisco.nxos collection will need some updates.

[alisonlhart]

I'm going to open another PR today adding allow-lists for specific versions of ansible. E.g. validate-modules:invalid-documentation and validate-modules:deprecation-mismatch. Networking brought these rules to our attention after merge.