PT: Fix test failures and PT mapping conflicts under WebRTC-PayloadTypesInTransport

This CL addresses multiple test failures in rtc_pc_unittests when the
WebRTC-PayloadTypesInTransport field trial is enabled:

1. Reverts a too-permissive directionality check bypass in
pc/codec_vendor.cc to restore correct negotiation of kInactive via
reversed offer direction, fixing legacy AudioCodecsAnswerTest
failures.

2. Adds BUNDLE support to FakePayloadTypeSuggester by mapping bundled
MIDs to share the same PayloadTypeRecorder instance.

3. Fixes TestBundleOfferWithSameCodecPlType by configuring bundle
groups on the fake suggester.

4. Avoids force-registering conflicting preferred payload types in
RegisterExpectations inside CodecLookupHelperForTesting if they are
already mapped. This allows fake suggester conflict resolution to
work correctly in tests.

5. Updates 15 asymmetric H265 level negotiation tests to use
CodecListsMatch instead of strict EXPECT_EQ, as TypedCodecVendor
does not pre-assign payload types in video_sendrecv_codecs().

Bug: webrtc:360058654
Change-Id: I9431d77b2e3eceba25c2df71f5fef69f70480495
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/477860
Reviewed-by: Tomas Gunnarsson <tommi@webrtc.org>
Commit-Queue: Harald Alvestrand <hta@webrtc.org>
Cr-Commit-Position: refs/heads/main@{#47887}