LP1859241 Angular holds patron search dialog

LP1859241 Angular holds patron search dialog

Implements a patron search dialog which may be instantiated directly
from the staff catalog holds placement interface.

Includes:

1. New patron module (which absorbs the existing PatronService)
2. New patron search component
3. Patron search component dialog wrapper.
4. Patron profile selector component which understands custom group
   display trees.
4. Fixes an issue with the grid where the 'datatype' was not always
   propagated to IDL fields.
5. Modifies the combobox to allow the caller to clear the value by
   passing a null value for the selectedId.

To Test:

[1] Navigate to the Angular staff catalog
[2] Perform a bib search
[3] Click 'Place Hold' next to a title.
[4] Click the 'Patron Search' button.
[5] Search for patrons and either double-click a search result row or
    single click then chose the 'Select' button.
[6] Confirm the selected patron is now chosen for holds placement.

Signed-off-by: Bill Erickson <berickxx@gmail.com>