Ephemerals should be available in late binding functions

[cfxegbert]

Late binding functions have access to implicits in the function but not to ephemerals.

Motivation
To get to an ephemeral in a late binding function I have to use context.resolved_ephemerals which is a list. I have to search through the list manually to get the ephemeral. Having the EphemeralBinding object will allow me to easily call get_range instead of searching the list.

[cfxegbert]

Looks like the ephemerals are available in the request object as a workaround. To be consistent it should be available as ephemerals when in_context() is true.