"Autogenerate" data files with data fallbacks and moved keys folder into jar resources (#927)

* Autogenerate keys and data files

* Update gacha html files

Accidentally pushed with old html files

* Keys no longer copied. No more manually retrieving listing files. Recursive directory creation

Removed unused code from old GC as well.

* Moved somethings and better errors

* Fixed resources from loading twice

* Data files fallback

src/main/resources/defaults/data/TowerSchedule.json

@@ -0,0 +1,5 @@
+{
+  "scheduleId" : 45,
+  "scheduleStartTime" : "2022-05-01T00:00:00+08:00",
+  "nextScheduleChangeTime" : "2022-05-30T00:00:00+08:00"
+}