LP1824709: Allow comboboxes inputs to have IDs

LP1824709: Allow comboboxes inputs to have IDs

This adds a new input, domId, for the combobox component.

A good way to test:

1) Download the Wave accessibility checker.
2) Go to one of the following screens:
  - Admin > Local > Course Reserves > Choose a course > Associate
    item from catalog
  - Admin > Local > Course Reserves > Choose a course > Associate
    brief record
  - MARC Batch Import
  - MARC Batch Import/Export > Inspect Queue
  - Staff Catalog Add to bucket
  - Staff catalog conjoined items
  - Hold cancel dialog
3) Right click and select "WAVE this page"
4) On the Details tab of WAVE, notice that there are several "Missing
   form label" errors.
5) Apply this patch.
6) Run WAVE again; notice that the number of missing form label errors
   has decreased.

Signed-off-by: Jane Sandberg <sandbej@linnbenton.edu>