[ER] Fix build with current QTermWidget master.
[AN] Fixed type error.
[AN] Added TypedMatcherBase::SyncWidgetTo() for #1618.
[AN] Don't set source ID for standard fields matchers.
[AN] MatchConfigDialog::SetFieldMatch() for #1618.
[AN] Call SetFieldMatch() when modifying.

This closes #1618.
[AN] Optimized case with empty plugin ID.