[TEST] Fixed delete/50_refresh REST test to work against multiple nodes

delete/50_refresh tests per shard refresh using refresh:true in delete api. We might run into troubles though if we have a replica that gets initialized after a doc was indexed and deleted, without a refresh, as that doc won't be found when searching against that specific replica shard (as a refresh happens automatically before a replica gets exposed as started).
[DOCS] Added a table with 0.90/1.0 compatibility and corresponding instructions
[TEST] Add basic test for /cat/shards/{index}

Basic REST test for rendering the cat/shards endpoint.