Utils for gacha history record subsystem

* Auto generate mapping files with command `java -jar grasscutter.jar -gachamap`

* Static file provider
  * For gacha record webpage
  * All static files should be stored at `GRASSCUTTER_RESOURCE/gcstatic/`
  * Can benefit other subsystem in future when webpages involved

src/main/java/emu/grasscutter/Grasscutter.java

@@ -60,6 +60,9 @@ public final class Grasscutter {
 				case "-handbook" -> {
 					Tools.createGmHandbook(); return;
 				}
+				case "-gachamap" -> {
+					Tools.createGachaMapping(); return;
+				}
 			}
 		}