Introduce eql search status API,
that reports the status of eql stored or async search.
GET _eql/search/status/<id>
The API is restricted to the monitoring_user role.
For a running eql search, a response has the following format:
{
"id" : <id>,
"is_running" : true,
"is_partial" : true,
"start_time_in_millis" : 1611690235000,
"expiration_time_in_millis" : 1611690295000
}
For a completed eql search, a response has the following format:
{
"id" : <id>,
"is_running" : false,
"is_partial" : false,
"expiration_time_in_millis" : 1611690295000,
"completion_status" : 200
}
Closes#66955
