Neuron weights set

[open-junius]

Description

Add set_weights, commit_weights, reveal_weights extrinsic in precompile contract

Related Issue(s)

• Closes #[1076]

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

If this PR introduces a breaking change, please provide a detailed description of the impact and the migration path for existing applications.

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

Screenshots (if applicable)

Please include any relevant screenshots or GIFs that demonstrate the changes made.

Additional Notes

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[open-junius]

https://github.com/opentensor/subtensor-js-tests/blob/main/src/evm/eth.neuron.weights.test.js e2e test added.

[sam0x17]

small merge conflict still

[sam0x17]

merge conflicts + some unsafe math

[open-junius]

merge conflicts + some unsafe math

will fix it.

[gztensor]

I think it is possible to execute a transaction that packs 100_000 bytes of data and sets first_position value at 0xFFFF, which will overflow this line and panic. Please use safe math.