LP1858138 Grid IDL field definition repairs and more

LP1858138 Grid IDL field definition repairs and more

* Deprecate showLinkSelectors, since FormatService now performs that
  logic under the covers.  Includes deprecation console warning.

* Fix Grid field IDL class extraction off-by-one error.  The code was
  stamping the source field with the class of the field's link target
  instead of the class the field actually belonged to.

* Allow for IDL field info extraction from the 'name' attribute when no
  'path' attribute is defined.

* Avoid console errors when clearing combobox values in grid filters.

Signed-off-by: Bill Erickson <berickxx@gmail.com>
Signed-off-by: Galen Charlton <gmc@equinoxinitiative.org>