Enable label/enum searching

ElementProviders may now include a searchable string representation of
the element they provide at a given location. By opting into this, the
RunStorage will provide automatic search functionality. The first user
of this is the EnumProvider, since that already represents enum elements
as strings. The next participant will hopefuly be the speciesprovider.

I also added code to the scripted data type finder that can convert
labels into search results. Whenever it is asked to find something, it
checks its label collection and finds any labels that match the search
string.

Searches are now slower and might need a performance improvement, but
they are much more useful as well.