Add /terminate API (#6745)

this is to speed up suspends, see
https://github.com/neondatabase/cloud/issues/10284

## Problem

## Summary of changes

## Checklist before requesting a review

- [ ] I have performed a self-review of my code.
- [ ] If it is a core feature, I have added thorough tests.
- [ ] Do we need to implement analytics? if so did you add the relevant
metrics to the dashboard?
- [ ] If this PR requires public announcement, mark it with
/release-notes label and add several sentences in this section.

## Checklist before merging

- [ ] Do not forget to reformat commit message to not include the above
checklist

control_plane/src/endpoint.rs

@@ -652,7 +652,9 @@ impl Endpoint {
                         }
                         ComputeStatus::Empty
                         | ComputeStatus::ConfigurationPending
-                        | ComputeStatus::Configuration => {
+                        | ComputeStatus::Configuration
+                        | ComputeStatus::TerminationPending
+                        | ComputeStatus::Terminated => {
                             bail!("unexpected compute status: {:?}", state.status)
                         }
                     }