gRPC Migration List of handler to review

[working progress]

Endpoint ready to review - return interface or struct:

1 - /v1/chain/get/stats PR #652.

2 - /v1/miner/get/stats PR #650.

3 - /_sign PR #585.

4 - /v1/_x2m/block/notarized_block/get current grpc-migration-v2 branch.

5 - /v1/_x2m/block/state_change/get PR #659.

6 - /v1/_x2m/state/get PR #660.

7 - /v1/_m2m/dkg/share PR #664 - Issue #665.

8 - /v1/_m2m/chain/start PR #667.

Endpoint using datastore.Entity:

1 - /v1/transaction/put PR #643 PutTransaction()

2 - /v1/client/put PR #638 PutClient()

3 - /v1/clinet/get PR #642 GetClientHandler()

4 - /v1/_m2m/round/vrf_share

5 - /v1/_m2m/block/verify

6 - /v1/_m2m/block/verification_ticket

7 - /v1/_m2m/block/notarization

8 - /v1/_m2m/block/notarized_block

Endpoint return HTML body:

1 - /_chain_stats PR #648 ChainStatsWriter()

2 - /_diagnostics/wallet_stats PR #649 GetWalletStats()

3 - /_hash PR #586

4 - /v1/config/update & /v1/config/update_all - PR #598

5 - /v1/client/put PR #638