Configure workspace inheritance in the Web UI, in the API and in the CLI
### User story
As a workspace owner, I can modify the workspace inheritance list either through the Web UI, through the API or with the CLI.
In the Web UI, I can create an ordered list of workspaces among:
- the workspaces from the current scope that I have access to
- all the public workspaces from other scopes
- the workspaces that are already in the inheritance list (in case they have been added by someone else that had broader access than me)
### Error handling
- The API refuse to add private workspace from other scopes in the inheritance list
- The API fails for non-existing workspaces
### Implementation plan
- [x] Add the API (!2115)
- [x] Add the Web UI (!2143)
- [x] Add the CLI in debusine-client (!2157)
### Open questions
* Should the API work with workspace IDs or with fully qualified names of workspaces (e.g. debian/developers) or accept both interchangeably?
### Notes
This issue description can be modified to integrate feedback from
comments and from associated merge requests.
issue