[Rust][DataFusion] Add input_file_name function

[asfimport]

For lineage and diffing purposes (used by protocols like DeltaLake) it can be useful to know the source of input data for a Dataframe. This adds the input_file_name function which, like Spark, returns the name of the file being read, or NULL if not available.

Reporter: Mike Seddon / @seddonm1

PRs and other links:

• GitHub Pull Request #9944
• GitHub Pull Request #9976

_{Note: This issue was originally created as ARROW-12290. Please see the migration documentation for further details.}

[asfimport]

Joris Van den Bossche / @jorisvandenbossche:
Should this be moved to https://github.com/apache/arrow-rs/ or https://github.com/apache/arrow-datafusion?

[asfimport]

Todd Farmer / @toddfarmer:
This issue was last updated over 90 days ago, which may be an indication it is no longer being actively worked. To better reflect the current state, the issue is being unassigned. Please feel free to re-take assignment of the issue if it is being actively worked, or if you plan to start that work soon.