feat: add --grpc client option

[aaronc]

Description

Ref #13283 (comment).

Adds:

• --grpc flag to specify a gRPC URL which gets used for queries instead of ABCI query
• --grpc-insecure flag to disable TLS (needed for insecure endpoints)

I tested locally with endpoints from https://github.com/cosmos/chain-registry/blob/master/cosmoshub/chain.json and this works, but I am bothered by the --grpc-insecure flag always being required.

This seems cleanly back-portable.

---

Author Checklist

All items are required. Please add a note to the item if the item is not applicable and
please add links to any relevant follow up issues.

I have...

• included the correct type prefix in the PR title
• added ! to the type prefix if API or client breaking change
• targeted the correct branch (see PR Targeting)
• provided a link to the relevant issue or specification
• followed the guidelines for building modules
• included the necessary unit and integration tests
• added a changelog entry to CHANGELOG.md
• included comments for documenting Go code
• updated the relevant documentation or specification
• reviewed "Files changed" and left comments if necessary
• confirmed all CI checks have passed

Reviewers Checklist

All items are required. Please add a note if the item is not applicable and please add
your handle next to the items reviewed if you only reviewed selected items.

I have...

• confirmed the correct type prefix in the PR title
• confirmed ! in the type prefix if API or client breaking change
• confirmed all author checklist items have been addressed
• reviewed state machine logic
• reviewed API design and naming
• reviewed documentation is accurate
• reviewed tests and test coverage
• manually tested (if applicable)

[odeke-em]

Thank you for working on this change @aaronc and great to catch you on here, long time! I've added some suggestions about early returns, please take a look.

[odeke-em]

Can we please invert this condition and return early if .GRPCClient != nil or if !flagSet.Changed?

[aaronc]

But we don't actually want an early return. This isn't an error condition. It follows the same pattern as the rest of the function.

[odeke-em]

Early returns ease readability and reduce nesting. This code incurs 3 levels of nesting that could be trivially cut out just by early returns.

[aaronc]

But look at the rest of the function. This is not an early return condition. I know this is the last clause in the function, but adding an early return here would just make maintenance of this function harder because it doesn't fit the general pattern in the rest of the function.

[odeke-em]

Left to your discretion :-)

[odeke-em]

Let's also do an early return here if grpcURI == "" { return clientCtx }

[aaronc]

Thank you for working on this change @aaronc and great to catch you on here, long time!

Likewise @odeke-em 👋

[aaronc]

Can I get a review on this?

[amaury1093]

Nice! I remember there was a previous attempt to make cli queries go to grpc directly #10997, but can't remember why it was closed. Definitely happy to see this.