[Feat] Can we get lists of items separated by commas to ignore spaces?

[cmbarton]

Is your feature request related to a problem? Please describe.
A number of GRASS modules allow you to enter 2 or more items to an argument as a comma-separated list--e.g., x,y coordinates, lists of maps in for a PCA or series, etc. Often when this information is pasted from the clipboard or other sources, there may be one or more spaces between an item and a comma. This always causes the command to fail with a sometimes uninterpretable error.

Describe the solution you'd like
It is pretty easy in Python to ignore whitespace in comma-separated lists. Can't we just parse comma-separated lists that go into arguments to ignore that whitespace? A poorly written argument with a comma followed by nothing would of course generate an error one way or another--as it should. But a complete list of comma-separated items would not even if there was some whitespace between items.