* feat: use app wildcards for apps if configured
* feat: relative_path -> subdomain
- rename relative_path -> subdomain when referring to apps
- migrate workspace_apps.relative_path to workspace_apps.subdomain
- upgrade coder/coder terraform module to 0.5.0
* Initial support for metadata in provisioner API and Terraform provisioner
* add support for nullable metadata fields
* handle metadata fields in provisionerd and API
This cleans up agent association code to explicitly map a single
agent to a single resource. This will fix#1884, and unblock
a prospect from beginning a POC.