Hide free instances of HashCheckParamInfo into functions

[palas]

Changelog

- description: |
    Hid free instances of `HashCheckParamInfo` to improve type safety
  type:
  - refactoring    # QoL changes

Context

This addresses post-merge reviews in #915

How to trust this PR

Ensure this is a refactoring and that the new design is robust.

Checklist

• Commit sequence broadly makes sense and commits have useful messages
• New tests are added if needed and existing tests are updated. See Running tests for more details
• Self-reviewed the diff

[smelc]

More consistent with the rest of the same file, nice 💯

[Jimbo4350]

Have a look at pScriptDataOrFile. It is generically defined.

We create a new parser and name it appropriately e.g pTxHashScriptData

So we can remove HashCheckParamInfo.