Avoid using "wait" to mean things other than block

[jaredhoberock]

Names such as stream_wait_and_invalidate[https://github.com/agency-library/agency/blob/master/agency/cuda/detail/future/event.hpp#L369] are confusing to C++ programmers who expect "wait" to mean something involving blocking the calling thread.

"depend" is a better word indicating what is actually going on in such APIs.