GraphQL query for latest block height observed

[deepthiskumar]

Latest block that is received and passed initial validation. May or may not be added to the frontier

[duccas]

If this request will be fast, we can use it in HAProxy health checks to compare the latest block with other nodes and exclude lagging ones. This ensures stable public RPC performance for zkApps for example.

[deepthiskumar]

@duccas Looks like there is already a graphQL command daemonStatus to check if a node is behind.
The field highestUnvalidatedBlockLengthReceived is the max height of a block received but not necessarily validated
The field highestBlockLengthReceived gives you the height of a valid block that a node received but may not have processed yet or failed to process
The field blockchainLength gives you the height of the block that a node has processed and added to its local state.