x11-toolkits/py-qt[56]-chart: Rename to *-charts

Move x11-toolkits/py-qt[56]-chart to x11-toolkits/py-qt[56]-charts to be
consistent with the names of their C++ counterparts.

Qt has always pluralized the Charts module, but PyQt didn't pluralize it
until Qt6. With the upcomming addition of the PyQt Graphs module, keeping
this singular would be even more awkwark.

While here:
Add all pyqt5 components except webengine to the devel/py-qt5 metaport
to be consistent with the devel/py-qt6 metaport.