Setting > Inventory > Holdings > Holdings source, predefined values (FOLIO, MARC). Deprecate action buttons.

Overview: The predefined holdings source values (FOLIO, MARC), is to be implemented as not editable values in the UI: Settings > Inventory > Holdings > Holdings source. When we did the first implementation UIIN-1229, story 5 and story 6 were pulled out. The backend work is completed with MODINVSTOR-590, so what is missing is ui-only work in order to get the two action buttons 'edit pen' and 'waste basket' deprecated.

Scenarios:

1. Scenario
   • Log into FOLIO Snapshot https://folio-snapshot.dev.folio.org/, go to Settings > Holdings > Holdings sources
   • When selecting Holdings sources, the Holdings sources setting page displays in the 3rd pane
   • Then Holdings sources has following predefined terms, with source set to 'folio'. These values are non editable values
     • FOLIO - a non editable source
     • MARC - a non editable source
       See UX here: