[Feature] API endpoints for ST sync execution

Saw that issue:
https://forum.stackstorm.com/t/is-it-possible-to-execute-an-action-synchronously-with-the-api/99

So thought a good Async to sync ST execution can be in the following form.
concatenating sync/ for the relevant new endpoints.

Asynchronous Pattern:

With the asynchronous pattern, if the remote server indicates that the request is accepted for processing with a 202 (Accepted) response, we will have to keep polling a URL specified in the response's location header until reaching a terminal state.

This pattern specifies that after an HTTP action calls or sends a request to an endpoint, service, system, or API, the receiver immediately returns a "202 ACCEPTED" response. This code confirms that the receiver accepted the request but hasn't finished processing. The response can include a location header that specifies the URI and a refresh ID that the caller can use to poll or check the status for the asynchronous request until the receiver stops processing and returns a "200 OK" success response or other non-202 response.

So Once we are creating an execution (Should return 202 status code with the location URL):
curl -X POST -H 'Connection: keep-alive' -H 'Accept-Encoding: gzip, deflate' -H 'Accept: */*' -H 'User-Agent: python-requests/2.11.1' -H 'content-type: application/json' -H 'X-Auth-Token: da5ecf3b0ab841008d663052fe95cddd' -H 'Content-Length: 69' --data-binary '{"action": "core.local", "user": null, "parameters": {"cmd": "date"}}' http://127.0.0.1:9101/v1/sync/executions
The response can include a location header that specifies the URI.
I.E:
<HOST>/api/v1/sync/executions/{id}

Full URL for polling will be like (Getting ST execution) (Should return 202 status code until it has a final state and will return a "200 OK" success response):
curl -X GET -H 'Connection: keep-alive' -H 'Accept-Encoding: gzip, deflate' -H 'Accept: */*' -H 'User-Agent: python-requests/2.11.1' -H 'X-Auth-Token: da5ecf3b0ab841008d663052fe95cddd' http://127.0.0.1:9101/v1/sync/executions/58de117e49d4af083399181c

An HTTP 202 response should indicate the location and frequency that the client should poll for the response. It should have the following additional headers:

Start by reviewing the existing execution API entry points alongside the proposed POST /v1/sync/executions and GET /v1/sync/executions/{id} endpoints. The work is complete when creation returns 202 with a Location and Retry-After header, polling remains 202 until a final state, and then returns 200 or another appropriate terminal response.