Addresses #17015 by introducing a new startWithOptions. The only option is currently is a flag
to use the provided URI as is, without modification when passed to the server. Normally, this
is not needed nor desired. However, some REST APIs may have requirements that cannot be satisfied
with the default handling.
Make to avoid releasing request's connection twice.
Change the `Request.connection` field optional. This field is null while the connection is released.
Fixes#15965