Change function names to make their purpose clear

Changes to limit line length to 80 chars

Remove store and pass it as argument plus mod sharding based on attributes

Parse Mutation block from GraphQL

Remove gql module's dependency on query. Make it the other way round.…

Correction to execution instruction and reference to headers

Remove gql module's dependency on query. Make it the other way round. GraphQL query string, now gets converted into query.SubGraph as an additional step run via query.ToSubGraph.

Add rocksDB merging code