[HBCK2] extraRegionsInMeta need supoort delete extra regions when table not exist

Some times, we delete one table dir on hdfs, we need use hbck2 to fix region info in hbase:meta...

but some times, we use hbase shell delete the table state uncarefully，just like execute:

deleteall 'hbase:meta','t1,xxx' (it not prevented...)

then the table state lose

when we want to use extraRegionsInMeta to remove these unuseful regions in meta...but it failed,beacuse the table is not exist..

I think we should support do extraRegionsInMeta when table not exists...or there are other method to fix it?