Update ecosystem to v0.15.x PS release

I'm opening this issue to track the work we need to do for ecosystem update to the v0.15.x release.

Below are all the Issues and PRs with the "purs-0.15" and "type: breaking change" labels across the core, contrib, web, and node libraries. This helps us see what can be done but not necessarily what must be done:

I'll update this opening comment with more links and info as we get closer to this.