Filter out from trips json any options that have start/end time more
than [x] hours from the user's desired start/end time. [x] defaults
to 2 hours. [Fixes #71234762]
Paratransit options now have a configurable minimum duration, which
defaults to 2 hours (in _oneclick.rb).  So they now have starts &
ends.

In addition, unless SKIP_DYNAMIC_PARATRANSIT_DURATION is set, we also
hit OTP to get car trip time, and multiply that by a factor (also
configurable, system-wide at the moment) to get a dynamic estimate.

At the moment with the factor set to 2x, in PA at least most trips
are using the static minimum duration.

[Fixes #71222998]