Add `template_usage_stats` table for aggregating tempalte usage data.
Data is rolled up by the `UpsertTemplateUsageStats` query, which fetches
data from the `workspace_agent_stats` and `workspace_app_stats` tables.
* chore: add /v2 to import module path
go mod requires semantic versioning with versions greater than 1.x
This was a mechanical update by running:
```
go install github.com/marwan-at-work/mod/cmd/mod@latest
mod upgrade
```
Migrate generated files to import /v2
* Fix gen
