Enhancement: Keep withdrawn study type field listed in "more information"

[hofmannc]

Testserver: qa imeji
Browser: ff
Version: 4.6 - build date 2019-08-30 12:57:36
User: admin

Actions:
admin -> configuration -> collections -> enter list of study types -> save
edit collectin informatin -> assign several collectins with study types
admin -> configuration -> collections -> delete list of study types

Observation:
Collections are still correctly searchable and listed in facet, but entry in collection "more information" is not listed anymore

Enhancement: Make earlier assigned study types still available in "more info" (and maybe in "edit collections", too?) -> so user is able to verify his search result