Support fill by value for downdowns

[psav]

In the old framework we had the ability to fill a Select/Downdown by Value as well as by Text. In WT we can currently only fill by Text. The consequence is that some dropdowns are set up in such a way that they are showing a name and then another name in brackets, like name (name), or something similar. To get around this, the team has implemented a partial match, but the problem with this is that if another entry is there with the same name or beginning with the same name, then it could do an erroneous match. I propose that we introduce a by-value/by-text system so that we can setup a widget to be by-text by default and then allow the user to fill it with by-value to override, and of course the opposite is also true. This isn't hitting us yet, but I believe it will do sooner or later.