Lock transfers

[gztensor]

Description

When a stake transfer happens between different coldkeys on the same netuid, the lock will be transferred. Using this algorithm:

1. Read total alpha of the coldkey on this netuid. If total alpha is lower than amount transferred, error out with StakeUnavailable.
2. Create a new mutable variable “remaining_to_transfer”.
3. Read the lock for this coldkey and roll forward.
4. If no lock exists, return ok
5. Calculate available stake by subtracting locked_mass and unlocked_mass from total alpha.
6. Reduce remaining_to_transfer by min(remaining_to_transfer, available stake)
7. If result is non-zero, reduce remaining_to_transfer by min(unlocked_mass, remaining_to_transfer), reduce unlocked_mass on the source coldkey by the same amount, increase unlocked_mass on the destination coldkey by the same amount.
8. If result is non-zero, check the hotkey match between source and destination coldkey locks (if destination coldkey lock exists). If no match, error out with LockHotkeyMismatch, otherwise, reduce remaining_to_transfer by min(remaining_to_transfer, locked_mass), reduce locked_mass on the source coldkey by the same amount, increase locked_mass on the destination coldkey by the same amount, reduce conviction on the source coldkey proportionally, and increase conviction on the destination coldkey proportionally.

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):

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 ./scripts/fix_rust.sh 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