[MAYA-126067] Export to usd dialog - expose preserveUVSetNames

**Is your feature request related to a problem? Please describe.**
The UI for export to USD doesn't expose the `preserveUVSetNames` option, so when I'm trying to do a maya-arnold round trip where my materials reference specific uvSets by name I need to go to the script editor as I can't toggle this option on to stop the UVset renaming behaviour.

**Describe the solution you'd like**
A way to set this option to on/off. Ideally it'd be default set on when selecting the Arnold plugin configuration (but should be deselectable - there may be a case where i don't want this)

**Describe alternatives you've considered**
Running a custom command line/shelf button.

**Additional context**
If there are any other flags that aren't UI exposed, if I could get a generic way to put them in or set/unset i'd be happy with that.

Start at the Maya USD export dialog and trace how the Arnold plugin configuration exposes export options, then locate the existing preserveUVSetNames command or setting used from the script editor. Done means the dialog can toggle preserveUVSetNames on and off, with the requested Arnold default behavior if supported.

Written by the indexing model from the issue text.