Add unit tests for tags queries

[the-mikedavis]

Checklist: ✅

• [x] All tests pass in CI.
• [x] The script/parse-examples passes without issues.
• [x] There are sufficient tests for the new fix/feature.
• [x] Grammar rules have not been renamed unless absolutely necessary.
• [x] The conflicts section hasn't grown too much.
• [x] The parser size hasn't grown too much (check the value of STATE_COUNT in src/parser.c).

(mostly doesn't apply as this PR just adds new unit tests)

Following up on https://github.com/tree-sitter/tree-sitter/pull/1547, this PR adds unit tests for the tags queries. Let me know if there are edge cases I missed!

~Also included is a bump to tree-sitter-cli v0.20.6 which has the new tags testing code.~

[amaanq]

if it would still be useful then rebase/regenerate and I can merge