Change read path Bloom check to work with Cells with out any copy

Currently the read path though it works with Cells, still does go with the assumption that we need to copy the Cells to KeyValue's key format and then use the byte[] version of hash() function to calculate the Bloom hash. In case of incoming cell's being KeyValue type we try to use the KeyValue.getKey(), KeyValue.getKeyOffset() APIs. With this sub-task we will get rid of all those and things will work with Cells.