Add version verification script/workflow

[theory]

Write a script that examines the version in META.json, pg_clickhouse.control, doc/pg_clickhouse.md, and CHANGELOG.md, and the $GITHUB_REF_NAME environment variable (when $CI is set and it's a version) to ensure they're compatible. Things to check:

• The version in META.json is canonical. Both instances of it there should be the same
• The version in pg_clickhouse.control must be the same as the x.y part of the version from META.json
• Aside from 0.1, the x.y part must always have an upgrade script in the sql directory
• If a workflow is running for a semantic version tag, the tag must be the same as the full x.y.z version from META.json version
• PG_MODULE_MAGIC must be the same full x.y.z version from META.json

Any violations should raise an error (or be automated away).