refactor: utility methods into separate internal package for reuse in std library

[ivokub]

Description

Refactor the utility methods to internal package for convenient reuse.

Type of change

• Refactoring, no breakage

How has this been tested?

All existing unit tests succeed.

Checklist:

• I have performed a self-review of my code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• I have added tests that prove my fix is effective or that my feature works
• I did not modify files generated from templates
• golangci-lint does not output errors locally
• New and existing unit tests pass locally with my changes
• Any dependent changes have been merged and published in downstream modules

[ivokub]

Pinging @Tabaie - I also refactored some stuff related to GKR and compression. The motivation was to have a clean set of packages in std/, as the algo_utils and test_vector_utils packages seemed to be utility packages. But if it does break any current work, then I can revert the commit a111226

[yelhousni]

LGTM and works seamlessly on my other branch!