Annotate content (CollectionVersion and LegacyRole) with a `wisdom_index` boolean, that defaults to true

Add model to store this boolean, the enduser will set this boolean at the Namespace level (for collections) and at the LegacyNamespace level (for standalone legacy roles). The data in this model does not need to sync outside Galaxy, it is only exposed on the api.

Draft model doc started: https://hackmd.io/LpBWeOkUQQ-XYW6W4plLnA?view