[+] 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/java/icu/samnyan/aqua/net/games/mai2/Mai2Import.kt

@@ -48,4 +48,4 @@ class Mai2Import(
 ) {
     override fun createEmpty() = Maimai2DataExport()
     override val userDataRepo = repos.userData
-}
+}

src/main/java/icu/samnyan/aqua/net/utils/ErrorResponse.kt

@@ -17,6 +17,8 @@ class ApiException(val code: Int, message: Str) : RuntimeException(message) {
     fun resp() = ResponseEntity.status(code).body(message.toString())
 }
 
+fun Exception.simpleDescribe(): String = if (this is ApiException) "E${code}" else javaClass.simpleName
+
 @ControllerAdvice(basePackages = ["icu.samnyan"])
 class GlobalExceptionHandler {
     @ExceptionHandler(ApiException::class)