The new Agent API needs an interface for ServiceBanners, so this PR creates it and refactors the AGPL and Enterprise code to achieve it.
Before we depended on the fact that the HTTP endpoint was missing to serve an empty ServiceBanner on AGPL deployments, but that won't work with dRPC, so we need a real interface to call.
* 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
* chore: rename "InsertOrUpdate" to Upsert around the codebase
The shorter name uses up less line width, is easier to read
and is used more often.
* make gen
* feat: enable enterprise users to specify a custom logo
This adds a field in deployment settings that allows users to specify
the URL to a custom logo that will display in the dashboard.
This also groups service banner into a new appearance settings page.
It adds a Fieldset component to allow for modular fields moving forward.
* Fix tests
