* Avoid joins with header and transaction tables while getting logs
* Update getLogs GQL API to accept multiple addresses
* Update version
* Update unit tests
* getLogs API changes to return txHash, make contract arg optional.
* Populate log index.
* Add test for txn hash in GetLogs request.
* Convert tx string to common.Hash after fetching.
Co-authored-by: Arijit Das <arijitad.in@gmail.com>