Add version field to metadata collected from files and dataframes

[skrawcz]

Adds version field to metadata collected for files and dataframes.

Implements #751.

This is to formalize schema at a Hamilton level.

We can always extend this to have someone provide
their own callback function to produce this.

We use the __ syntax to help show that this is internal.

Changes

io/utils metadata functions.

How I tested this

• locally via unit tests

Notes

Checklist

• PR has an informative and human-readable title (this will be pulled into the release notes)
• Changes are limited to a single goal (no scope creep)
• Code passed the pre-commit check & code is left cleaner/nicer than when first encountered.
• Any change in functionality is tested
• New functions are documented (with a description, list of inputs, and expected output)
• Placeholder code is flagged / future TODOs are captured in comments
• Project documentation has been updated if adding/changing functionality.

[elijahbenizzy]

Seems reasonable