[gnokey] Add support for queries on a specific height

[leohhhn]

Description

Currently, calling queries at a specific height is not supported, even though the --height flag exists in gnokey. We should either implement this, or remove the flag until the functionality is implemented. Same goes for the --prove flag.

[moul]

What are you hoping to query at a specific height? Do you have any hypothetical gnokey usage examples to share?

[linhpn99]

#2234
@leohhhn Please consider this PR if we don't have a specific plan for implementing the logic for the two mentioned commands

[leohhhn]

@moul

I found it useful to check balances and other things at times when I was writing & testing smart contracts previously. It's not a major usecase, more of a nice-to-have.

I think it would be cool to have it, but if you disagree, I think we should remove it from the gnokey binary, as well as from the docs.

@linhpn99 Thanks, let's wait for @moul's opinion on this.

[moul]

I’m against supporting custom height for balance checking. This is the role of an indexer, like Gnoscan. I suggest making feature requests to them or the DevX team, or consider defining specs for a new indexer.

I stay open for other queries such as retrieving a full block or something that’s cheap to compute.