Migrate the Forum to the Discourse SaaS

[x] Ensure the updated privacy statement is ready to go
[x] Provision a discourse account
[x] Update discourse to latest version
[x] Schedule maintenance window - post a notice in the forum that we'll be doing a migration
[x] During maintenance window - backup forum and restore on discourse.org
[x] Add new privacy notice
[x] Setup sticky banner pointing to new privacy notice
[x] Follow up on original thread asking how GDPR is handled in the forum

solid / team