API endpoint to "Mark all todos as closed"
Problem to solve
We are introducing a button to "Close all" To-Dos in #215046 (closed). Once that is introduced, the interface will differ from the API, which does not allow To-Dos to be marked as closed.
Proposal
Add an API endpoint to "Mark all todos as closed".
Further details
This API endpoint would have the same functionality as the new "Close all" button in the interface.
Permissions and Security
Same permissions as the "Mark all todos as done" endpoint.