fix(gc): refresh current_tipset together with current_epoch after sleeping

[hanabi1224]

Summary of changes

This PR fixes a potential bug in GC flow that after sleeping(10h), only current_epoch is refreshed but the 10h old tipset is used for the filtering step.

It also refactors a few chain traversal APIs to be more generic in preparation for lite GC implementation that is tracked by #5121

Changes introduced in this pull request:

Reference issue to close (if applicable)

Closes

Other information and links

Change checklist

• I have performed a self-review of my own code,
• I have made corresponding changes to the documentation. All new code adheres to the team's documentation standards,
• I have added tests that prove my fix is effective or that my feature works (if possible),
• I have made sure the CHANGELOG is up-to-date. All user-facing changes should be reflected in this document.

[LesnyRumcajs]

Great! It might be worth mentioning in the changelog.

[hanabi1224]

Great! It might be worth mentioning in the changelog.

@LesnyRumcajs Changelog updated