YACI-CLI allow block time of less than 1 second

[0xtrossets]

As of now, block time on node start must be at least 1 second.
I would like to be able to set it to a shorter time like 0.5 second.

[satran004]

@0xtrossets Thanks for trying out Yaci DevKit.

During the initial release of DevKit, we had a default 3-node setup, and block times below 1 second was causing some instability.

Now that we have a single-node devnet, I think we can revisit this. It's just a soft check in the CLI code, so we can remove it in the next release if it works.

[0xtrossets]

That'd be great. Thanks