Initial commit for reworked select k indices function.

[damrobi]

Content

This PR includes a new function to perform the selection of k unique indices for the aggregated signature of mithril-stm. The goal of the new function is to improve readability and performances (memory and time) if possible.

Pre-submit checklist

• Branch
  • Tests are provided (if possible)
  • Crates versions are updated (if relevant)
  • CHANGELOG file is updated (if relevant)
  • Commit sequence broadly makes sense
  • Key commits have useful messages
• PR
  • All check jobs of the CI have succeeded
  • Self-reviewed the diff
  • Useful pull request description
  • Reviewer requested
• Documentation
  • Update README file (if relevant)
  • Update documentation website (if relevant)
  • Add dev blog post (if relevant)
  • Add ADR blog post or Dev ADR entry (if relevant)
  • No new TODOs introduced

Comments

Issue(s)

Relates to #YYY or Closes #YYY

[github-actions]

Test Results

    4 files  ±0    164 suites  ±0   23m 53s ⏱️ +21s
2 195 tests ±0  2 195 ✅ ±0  0 💤 ±0  0 ❌ ±0 
6 760 runs  ±0  6 760 ✅ ±0  0 💤 ±0  0 ❌ ±0 

Results for commit 5f0a015. ± Comparison against base commit 9f90c66.