Fix Intersection Reference and Signal Group Alignment Events

[iyourshaw]

Fixes the following issues found in integration testing:

• MAPs and SPaT from the same RSU were not being joined correctly for the Intersection Reference Alignment check.
• Signal Group Alignment events incorrectly produced when SPAT and MAP signal groups match.

The integration tests are described here:

• Intersection Reference Alignment

• Signal Group Alignment

Verified that after applying the fix, the integration tests pass.

Note that the key of the Intersection Reference Alignment events is changed to be the RSU ID instead or an RsuIntersectionKey object.