``loc='best'`` for ``legend`` now considers ``Text`` and ``PolyCollections``

The location selection ``legend`` now considers the existence of ``Text``

and ``PolyCollections`` in the ``badness`` calculation.

Note: The ``best`` option can already be quite slow for plots with large

amounts of data. For ``PolyCollections``, it only considers the ``Path``

of ``PolyCollections`` and not the enclosed area when checking for overlap

to reduce additional latency. However, it can still be quite slow when

there are large amounts of ``PolyCollections`` in the plot to check for.