feat(coderd): add dbcrypt package (#9522)

- Adds package enterprise/dbcrypt to implement database encryption/decryption
- Adds table dbcrypt_keys and associated queries
- Adds columns oauth_access_token_key_id and oauth_refresh_token_key_id
  to tables git_auth_links and user_links

Co-authored-by: Kyle Carberry <kyle@coder.com>

coderd/database/queries/dbcrypt.sql

@@ -0,0 +1,18 @@
+-- name: GetDBCryptKeys :many
+SELECT * FROM dbcrypt_keys ORDER BY number ASC;
+
+-- name: RevokeDBCryptKey :exec
+UPDATE dbcrypt_keys
+SET
+	revoked_key_digest = active_key_digest,
+	active_key_digest = revoked_key_digest,
+	revoked_at = CURRENT_TIMESTAMP
+WHERE
+	active_key_digest = @active_key_digest::text
+AND
+	revoked_key_digest IS NULL;
+
+-- name: InsertDBCryptKey :exec
+INSERT INTO dbcrypt_keys
+	(number, active_key_digest, created_at, test)
+VALUES (@number::int, @active_key_digest::text, CURRENT_TIMESTAMP, @test::text);