[EASI-3944] Notifications - On Discussion Replied Notification (#990)

* wip: draft of sending notifications on discussion reply

* wip: implementing PR feedback

* wip: implement various PR feedback

* wip: corrected actor ID to be reply creator ID and added discussion creator ID to meta

* fix: corrected notification recipient from actor to discussion creator

* feat: testing preview for discussion reply notification

* chore: updated postman collection

* fix: corrected activity meta base struct type

* chore: added comment to helper function

* chore: deleted unused generated resolver

* fix: revereted incorrectly changed user ID assignment

* removed irrelevant comment

* chore: added more assertions to unit test

MINT.postman_collection.json

@@ -1,9 +1,9 @@
 {
 	"info": {
-		"_postman_id": "32329f70-986e-430d-8a0b-4509ca71dab1",
+		"_postman_id": "e2043604-4cd9-443c-9267-db489feb92d8",
 		"name": "MINT",
 		"schema": "https://schema.getpostman.com/json/collection/v2.1.0/collection.json",
-		"_exporter_id": "20320964"
+		"_exporter_id": "20435042"
 	},
 	"item": [
 		{
@@ -2089,7 +2089,8 @@
 									"//     pm.collectionVariables.set(\"operationalSolutionSubtaskID\"+i, subtaskID);",
 									"// }"
 								],
-								"type": "text/javascript"
+								"type": "text/javascript",
+								"packages": {}
 							}
 						}
 					],
@@ -2099,7 +2100,7 @@
 						"body": {
 							"mode": "graphql",
 							"graphql": {
-								"query": "query currentUser {\n  currentUser {\n    notifications {\n      numUnreadNotifications\n      notifications {\n        __typename\n        id\n        isRead\n        inAppSent\n        emailSent\n        activity {\n          activityType\n          entityID\n          actorID\n                    metaData {\n            __typename\n            ... on TaggedInPlanDiscussionActivityMeta{\n                version\n                type\n                modelPlanID\n                modelPlan{\n                    modelName\n                }      \n                discussionID\n                content\n            }\n            ... on TaggedInDiscussionReplyActivityMeta {\n                version\n                type\n                modelPlanID\n                modelPlan{\n                    modelName\n                }                  \n                discussionID\n                replyID\n                content\n            }\n          }\n          createdByUserAccount {\n            commonName\n          }\n        }\n        createdByUserAccount {\n          commonName\n        }\n      }\n    }\n  }\n}\n",
+								"query": "query currentUser {\n  currentUser {\n    notifications {\n      numUnreadNotifications\n      notifications {\n        __typename\n        id\n        isRead\n        inAppSent\n        emailSent\n        activity {\n          activityType\n          entityID\n          actorID\n                    metaData {\n            __typename\n            ... on TaggedInPlanDiscussionActivityMeta{\n                version\n                type\n                modelPlanID\n                modelPlan{\n                    modelName\n                }      \n                discussionID\n                content\n            }\n            ... on TaggedInDiscussionReplyActivityMeta {\n                version\n                type\n                modelPlanID\n                modelPlan{\n                    modelName\n                }                  \n                discussionID\n                replyID\n                content\n            }\n            ... on NewDiscussionRepliedActivityMeta {\n                version\n                type\n                discussionID\n                replyID\n                content\n            } \n          }\n          createdByUserAccount {\n            commonName\n          }\n        }\n        createdByUserAccount {\n          commonName\n        }\n      }\n    }\n  }\n}\n",
 								"variables": ""
 							}
 						},