SOAR-0002 implementation

[czechboy0]

Motivation

Implements the approved SOAR-0002 proposal: #170

Modifications

• updates the function that computes content type names to be in line with v3 of SOAR-0002
• refactors the ContentType type a bit to make it harder to accidentally perform case-sensitive comparions where case-insensitive ones are required

Result

When an adopter passes the multipleContentTypes feature flag, they'll get the new logic as described in SOAR-0002.

Test Plan

• adapted unit tests for the contentSwiftName function
• enabled the proposal0001 feature flag as well, since they will be enabled together in 0.2.0, so makes sense to test the new world together
• this lead to a few more updates needed in the reference tests that weren't caused by 0.2.0 alone

[glbrntt]

LGTM