fix(EndPointsOverlay): Make setLocation optional

[binh-dam-ibigroup]

In response to opentripplanner/otp-react-redux#1272 (comment) , this PR makes the setLocation prop in the EndpointsOverlay optional (puts in the default noop handler as with other event handlers).

[daniel-heppner-ibigroup]

I feel less bad about requesting this change now that I see we already have noop as a default in here for other things

[binh-dam-ibigroup]

I feel less bad about requesting this change now that I see we already have noop as a default in here for other things

Maybe we'll have to remove the noops from here eventually?

[daniel-heppner-ibigroup]

I feel less bad about requesting this change now that I see we already have noop as a default in here for other things

Maybe we'll have to remove the noops from here eventually?

Yeah It's a really wacky approach...

[miles-grant-ibigroup]

I think a noop function is much cleaner than doing weird existence checks elsewhere! It's also computationally more efficient (fewer jumps)