generalize zcatalog.update_table_columns reordering

[sbailey]

desispec.update_table_columns makes some assumptions about the order of input columns while reordering the columns for output, while also trying to handle different *_TARGET columns in different inputs, etc. This is fragile if the input column order changes, e.g. #2363 . PR #2368 fixed the immediate problem while still having fragile assumptions about input column order for the more general case.

Revisit how that reordering is done and make the code robust to arbitrary input column order. Include unit tests to verify.