Allow search by g:a:v string

As a user, if I try to search using a keyword of the form <group>:<artifact>:<version>:<extension>:<classifier> I expect to see search results that match my search term.

This form matches the syntax supported by nxrm 2.

These search strings could be group:artifact, group:artifact:version, group:artifact:version:extension, or group:artifact:version:extension:classifier. Currently the query string used for the search field treats this as a valid search of the form <search field>:<value> which will return nothing (or it will just be an invalid query). When we think the keyword search might match this we could switch from a must term in the boolean to two should terms. One which builds a boolean search for the components of this search and one that does the normal keyword search in order to ensure that we get some results.