Consistent behavior between accessor methods with source kwarg

[aaron-schroeder]

I noticed a lot of repeated behavior that seems like it might benefit from being refactored into a common pattern.

Specifically came up with record-generating methods (like XXX):

• What to do if the source field(s) are missing (eg the records DataFrame is missing lat or lon columns when df.distance.records_from_position() ... currently returns None I think).
• What to do if the field already exists in the records DataFrame and the method is called with inplace=True.
• Re-usable behavior that allows choice between ['records', 'laps', 'summary', {other methods using records from other field(s)}