Feature Request: Fact Sources, return features dropped from v4

[bjeffries]

Both observations below are regarding features that were dropped from v4 in magma relating to fact sources.

Observation 1: The new magma fact sources page displays facts as a 1 to 1 mapping of trait to value, rather than 1 to many. This will quickly become unwieldy.

Recommendation: Display only the unique fact traits and group the corresponding values in a list like it is done in v4. The same logic applies to fact rules.

Observation 2: The new magma fact sources page no longer allows users to add a new value to an existing fact trait with a single button press.

Recommendation: Revise fact editing so that new values can be added to an existing fact like in v4.