Introduce ZeroMaxAmount error for add_stake_limit extrinsic.

[shamil-gadelshin]

Description

It was possible to have a successful add_stake_limit extrinsic with zero stake added. This PR fixes this error.
Here is the example: https://taostats.io/extrinsic/5338471-0009?network=finney

Related Issue(s)

• Closes Fail partial staking extrinsic if max amount is zero #1538

Type of Change

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• Documentation update
• Other (please describe):

Breaking Change

The PR introduces a new possible error.

Checklist

• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• I have run cargo fmt and cargo clippy to ensure my code is formatted and linted correctly
• I have made corresponding changes to the documentation
• My changes generate no new warnings
• I have added tests that prove my fix is effective or that my feature works
• New and existing unit tests pass locally with my changes
• Any dependent changes have been merged and published in downstream modules

Additional Notes

move_stake extrinsic shares the same logic get_max_amount_add within its get_max_amount_move method but the PR kept the previous logic.

[github-actions]

@opentensor/cerebrum / @opentensor/gyrus / @opentensor/cortex breaking change detected! Please prepare accordingly!

[shamil-gadelshin]

The recent changes refactor get_max_amount_move using ZeroMaxStakeAmount error that affects additional extrinsics like move_stake or swap_stake.

[shamil-gadelshin]

The recent changes update the benchmark version to V2.

[camfairchild]

@MichaelTrestman
Should add this to the docs