Clean small values from Alpha map.

[shamil-gadelshin]

Description

This PR adds a process that iterates through small number (10) of Alpha map entries each block and cleans values less than 10 RAO.

Related Issue(s)

• Closes https://github.com/opentensor/subtensor/issues/1567

Type of Change

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

Breaking Change

This PR clears alpha stake values. We need to be sure that we chose the constants correctly.

Checklist

• [x] I have performed a self-review of my own code
• [x] I have commented my code, particularly in hard-to-understand areas
• [x] 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
• [x] My changes generate no new warnings
• [x] I have added tests that prove my fix is effective or that my feature works
• [x] New and existing unit tests pass locally with my changes
• [ ] Any dependent changes have been merged and published in downstream modules