Splits up round table initialize, start, end and shutdown (#37665)

For planned change to how TGS initializes server instances ahead of time so rounds aren't tracked as being far longer than they really would be. Similarly end time split for a more accurate round duration.

code/__DEFINES/subsystems.dm

@@ -1,7 +1,7 @@
 //Update this whenever the db schema changes
 //make sure you add an update to the schema_version stable in the db changelog
 #define DB_MAJOR_VERSION 4
-#define DB_MINOR_VERSION 3
+#define DB_MINOR_VERSION 4
 
 //Timing subsystem
 //Don't run if there is an identical unique timer active