make() method for component router interface

This PR adds a make() method to the component router interface. This method is meant to clean up URLs and do a kind of pre-processing on them and is thus executed on each URL every time, regardless of SEF being turned on or off.

The specific task for this method is to provide a means to add the Itemid to a URL in the router. Since the component router is normally only loaded when SEF is switched on and then it is only meant to actually SEF the URL, this process needs to go into a second method, which is only aimed at cleaning up the URL and provide a way to add this Itemid.

Of course, we don't have to only add the Itemid here. We might add or remove other parts of the query, which ultimately makes processing the query in the actual build() method easier. Think of missing slug or a timestamp or renaming limitstart to start, etc.