Fix entry count massa module cache

[Leo-Besancon]

• document all added functions
• try in sandbox /simulation/labnet
  • if part of node-launch, checked using the resync_check flag
• unit tests on the added/changed features
  • make tests compile
  • make tests pass
• add logs allowing easy debugging in case the changes caused problems
• if the API has changed, update the API specification

Note: as we currently clear the cache in main when the node starts, this does not impact the current code.
It's only fixed to avoid potential future errors if this is changed.

As a result, this does not need to be versioned.

[Leo-Besancon]

Updated to simply clear cache in new, and setting the entry_count to 0.