[+] Metrics (#95)

* Add actuator and micrometer

* update

* [-] Remove unused import

* [O] Make code less verbose

* format

* refactor

---------

Co-authored-by: Azalea <22280294+hykilpikonna@users.noreply.github.com>

src/main/resources/db/migration/mariadb/V1000_20__keychip_session_game_id.sql

@@ -0,0 +1,2 @@
+ALTER TABLE allnet_keychip_sessions
+    ADD game_id VARCHAR(4) NULL;