[Captured Sites] Fix String To Field type when loading autofill profile.

Captured Sites test builds an autofill profile by converting strings to
ServerFieldType & HtmlFieldType.

Adding kAllHtmlFieldTypes to allow looping through valid HtmlFieldType.

Bug: 1007974
Change-Id: I9ae0d74b76858f7f38b941c1344a7994ab407309
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/4908847
Commit-Queue: Ian Struiksma <ianstruiksma@google.com>
Code-Coverage: findit-for-me@appspot.gserviceaccount.com <findit-for-me@appspot.gserviceaccount.com>
Reviewed-by: Christoph Schwering <schwering@google.com>
Cr-Commit-Position: refs/heads/main@{#1204938}