feat: Add initial AuthzQuerier implementation
- Adds package database/dbauthz that adds a database.Store implementation where each method goes through AuthZ checks
- Implements all database.Store methods on AuthzQuerier
- Updates and fixes unit tests where required
- Updates coderd initialization to use AuthzQuerier if codersdk.ExperimentAuthzQuerier is enabled
* chore: Use dbgen in unit test
- organizationparam_test
- templateparam_test
* Use dbgen in all unit tests vs insert methods
* fixup! Use dbgen in all unit tests vs insert methods
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Co-authored-by: Cian Johnston <cian@coder.com>
