Make nodes more resilient to local unrelated files during startup

There's a few things we can protect against being in the data dir on startup that might be around from older activity, tool usage, exports, etc on a 3.x -> 4.x update:
a) file ending with *-old.json
b) file ending with *.json or *idx.json

A trivial update to the filter on SSTableHeaderFix.java should protect against hitting these types of files on startup and throwing.