Add Finder Scope ability to pywwt

[jsub1]

Would allow launching and hopefully querying the WWT finder scope in pywwt and glue-wwt.

[pkgw]

Much of the Finder Scope UI is implemented in the webclient repo. Is the interest in something that hews pretty closely to the webclient/Windows UI look, or more a general mechanism for getting info about whatever's near/under the mouse cursor even if the UX is different?