[Cases] Version connectors domain and apis (elastic#162059)

## Summary

This PR versions the `connector` domain object and its corresponding
APIs

### Checklist

Delete any items that are not applicable to this PR.

- [x] [Unit or functional
tests](https://www.elastic.co/guide/en/kibana/master/development-tests.html)
were updated or added to match the most common scenarios

### For maintainers

- [x] This was checked for breaking API changes and was [labeled
appropriately](https://www.elastic.co/guide/en/kibana/master/contributing.html#kibana-release-notes-process)

---------

Co-authored-by: Kibana Machine <42973632+kibanamachine@users.noreply.github.com>

x-pack/plugins/cases/common/api/cases/case.test.ts

@@ -5,7 +5,7 @@
  * 2.0.
  */
 
-import { ConnectorTypes } from '../connectors';
+import { ConnectorTypes } from '../../types/domain/connector/v1';
 import {
   RelatedCaseInfoRt,
   SettingsRt,

x-pack/plugins/cases/common/api/cases/case.ts

@@ -10,7 +10,6 @@ import * as rt from 'io-ts';
 import { UserRt } from '../user';
 import { CommentRt } from './comment';
 import { CasesStatusResponseRt, CaseStatusRt } from './status';
-import { CaseConnectorRt } from '../connectors/connector';
 import { CaseAssigneesRt } from './assignee';
 import {
   limitedArraySchema,
@@ -32,6 +31,7 @@ import {
   MAX_BULK_GET_CASES,
   MAX_CASES_PER_PAGE,
 } from '../../constants';
+import { CaseConnectorRt } from '../../types/domain/connector/v1';
 
 export const AttachmentTotalsRt = rt.strict({
   alerts: rt.number,