This change completes the necessary API changes for import assertions
discussed in
https://docs.google.com/document/d/1yuXgNHSbTAPubT1Mg0JXp5uTrfirkvO1g5cHHCe-LmY.

The old ResolveCallback is deprecated and replaced with a
ResolveModuleCallback that includes import assertions.  Until
ResolveCallback is removed, InstantiateModule and associated functions
are modified to accept both types of callback, using the new one if it
was supplied and the old one otherwise.  An alternative that I chose not
to go with would be to just duplicate InstantiateModule and associated
functions for both callback types.

SyntheticModule::PrepareInstantiate's callback parameter was unused so I
removed it.

Bug: v8:10958
Change-Id: I8e9fbaf9c2853b076b13da02473fbbe039b9db57
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2551919Reviewed-by: Camillo Bruni <cbruni@chromium.org>
Reviewed-by: Marja Hölttä <marja@chromium.org>
Commit-Queue: Dan Clark <daniec@microsoft.com>
Cr-Commit-Position: refs/heads/master@{#71506}