Enhance cuttering of DVDs

[klinga]

Currently, CallNum macros use the first word of the title taken from the 245 field to create a cutter.
RDA rules instructing catalogers to record the title as it appears on the source often result in the inclusion of some introductory phrase in the 245, e.g., Emily Brontë's Wuthering Heights. The macro then uses this introductory phrase to construct a cutter, which contravenes our local policy of using the main title for cuttering (DVD MOVIE EMILY vs DVD MOVIE WUTHERING).

Idea: for DVD/TV call numbers, the CallNum macro should offer a choice to a cataloger when 246s are present in the record. The cataloger can then decide which form of the title should serve as a base for a cutter: 245 or any other 246s (similar as it happens for biography call numbers with multiple 600s present).