feat: Add initial AuthzQuerier implementation (#5919)

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

coderd/database/dbauthz/doc.go

@@ -0,0 +1,17 @@
+// Package dbauthz provides an authorization layer on top of the database. This
+// package exposes an interface that is currently a 1:1 mapping with
+// database.Store.
+//
+// The same cultural rules apply to this package as they do to database.Store.
+// Meaning that each method implemented should keep the number of database
+// queries as close to 1 as possible. Each method should do 1 thing, with no
+// unexpected side effects (eg: updating multiple tables in a single method).
+//
+// Do not implement business logic in this package. Only authorization related
+// logic should be implemented here. In most cases, this should only be a call to
+// the rbac authorizer.
+//
+// When a new database method is added to database.Store, it should be added to
+// this package as well. The unit test "Accounting" will ensure all methods are
+// tested. See other unit tests for examples on how to write these.
+package dbauthz