Resolves: fdo#73936 make FormFieldDropDowns a real fieldportion

split the checkbox and list and use a field portion for the list.
That way it knows how to line break correctly wrt hardspaces and doesn't hang
when the situation arises.

Change-Id: I46d73f19ef8e51e7c21c8783ce70bb80d98a784c
Related: fdo#73936 detect dropdown form fields as fields for spellchecking

so they will appear grayed in the spell check preview (they don't appear
at all yet, they will in later commits)

Change-Id: Ic0c6fe2979c7c731d0efb85c747afca2268abc53
Related: fdo#73936 expand FormFieldDropDowns in ModelToViewHelper

when EXPANDFIELDS is set. i.e. for spell and grammar checking

Change-Id: I8c524f0cd584c9d6043dece5c1b736afb254b7c0
Related: fdo#73936 allow ModelToViewHelper to not expand footnotes..

but continue to expand fields. No change to anything yet, but
should allow this to be reused in SwTxtNode::GetExpandText

Change-Id: I4dbfc454d498fc85a918b0e43e68c219cbc37a21
Related: fdo#73936 use ModelToViewHelper to expand SwTxtNodes

ModelToViewHelper knows about formfield dropdown lists
so their content gets expanded, which means that
in the spelling dialog the dropdowns get shown and
are detected as fields

Change-Id: If23d44c6189a73d04205816a32e863161f7f38ef
Related: fdo#73936 for spelling restrict formelements-as-fields..

to dropdowns to be on the safe side for now anyway.

Change-Id: I88a73fe37b39306c6b24226e3b02c702d992ecb0
callcatcher: update unused code

Change-Id: Iefb8aa92a143fd192c382a0e18a632a0888cc511