ItemsAdder resource-pack diagnostics

## Modern atlas (1)

[Pack] Found 1 model file with no static item or block reference.
  Affected Versions: 1.21.11, 26.1.1, 26.1.2, 26.2
  Technical details:
    Fallback contexts: item 1, block 0
    Source user content pack: 1

  These files exist in the generated pack; they are not missing or invalid by themselves.
  Check them only if a configured item or block was expected to use them.

  Unreferenced model files from resource packs (1)
    No item declaration or blockstate in the pack references these files.
      base (1):
        - base:diamondsword
          File: contents/base/resourcepack/base/models/diamondsword.json
          Context: item; source: user content pack; reason: folder fallback; no item declaration root