load store example, make necessary APIs public

[drahnr]

What does this PR accomplish?

At some point during refactoring some items became private that ought to be public. This provides a temporary solution to make ends meet. A proper IO API is pending.

• 🩹 Bug Fix

Closes #188 .

Changes proposed by this PR:

An example and exposing primitive types.

Notes to reviewer:

Yet to check, if actual content equivalence is checked.

📜 Checklist

• [x] Test coverage is excellent
• [x] All unit tests pass
• [x] The juice-examples run just fine
• [ ] Documentation is thorough, extensive and explicit