REST API endpoint streamlining and cleanup (#133)

* Consolidate engine_info api calls

* Change api methods to use POST when possible

* Delete engine API cleanup

* Remove redundant installed_engines endpoint

* Update proxy to use similar named methods to new API calls

* More API cleanup

* Jobs API cleanup

* More jobs API cleanup

* Fix add jobs error due to null queue

* Remove unnecessary full_status and snapshot API endpoints

* Streamline add job POST endpoint

* Fix test after method name change

tests/test_distributed_job_manager.py

@@ -127,7 +127,7 @@ class TestFindAvailableServers:
         mock_get_props.return_value = {'api_version': '0.1', 'system_os': 'macos'}
 
         mock_proxy = MagicMock()
-        mock_proxy.is_engine_available.return_value = {
+        mock_proxy.get_engine_availability.return_value = {
             'available': True,
             'hostname': 'server-1.local',
         }
@@ -136,3 +136,4 @@ class TestFindAvailableServers:
         result = DistributedJobManager.find_available_servers('blender')
         assert len(result) == 1
         assert result[0]['hostname'] == 'server-1.local'
+        mock_proxy.get_engine_availability.assert_called_once_with('blender')