[FEA] First-class client drivers to make sure cached config does not give surprising bug

[vaimdev]

Is your feature request related to a problem? Please describe.
Cache in pygraphistry._config always give unpredictable results and bug

From Leo, https://graphistry.slack.com/archives/C01SP02UE9K/p1747887077708659?thread_ts=1747885157.883929&cid=C01SP02UE9K

we really need to add to pygraphistry first-class client drivers, e.g.,
g_client: Plottable = graphistry.register(...)
....
and then guarantee global changes to register do not impact anything descended from g_client

Describe the solution you'd like

like

class PyGraphistry:

  is_client = False

  def register(...):
     g = self.bind()
     g.is_client = True  # no longer users global config map but a local
     g._config = {}
     ...
     return g