arrow

ARROW-9264: [C++][Parquet] Refactor and modernize schema conversion code

Split this off from ARROW-8493 because enough code moved around to
warrant a review without other functional changes.

- Rename max_ to either current_ or removed entirely
- During SchemaField generation remove one check for grouped
  child fields.
- Add a field that will be required for generalized resolution
  ARROW-8493
- Use Result<> instead of output parameter for type conversions.
- Move code from reader_interal to schema.cc to align function declarations with header file.

Closes #7578 from emkornfield/parquet_resolution

Authored-by: Micah Kornfield <emkornfield@gmail.com>
Signed-off-by: Wes McKinney <wesm@apache.org>