Until now the "widget" attribute used in the search view was meant to
force the type of a field regardless of its definition. This system was
implemented quite a long time ago and is now useful in only one case:
searching for "reference" fields (we want them considered as char fields
else it is impossible to search on them).
This is why this commit completely removes the "widget" attribute
support in search views while consistently casting the "reference"
fields as "char" fields in the search bar.
Task 2061795
Julien Mougenot
a7657fbf84