feat: add subscriptions and rework interfaces

api/gql_ev/common.graphqls

@@ -0,0 +1,43 @@
+scalar Time
+scalar Map
+
+type Connection {
+    paging: PageInfo!
+    edges: [Edge!]!
+}
+input PageInput {
+    idx: Int = 0
+    count: Int = 30
+}
+type PageInfo {
+    next: Boolean!
+    prev: Boolean!
+
+    begin: Int!
+    end:   Int!
+}
+interface Edge {
+    id: ID!
+}
+
+type Meta {
+    eventID: String! @goField(name: "getEventID")
+    streamID: String!
+    created: Time!
+    position: Int!
+}
+
+directive @goModel(
+	model: String
+	models: [String!]
+) on OBJECT | INPUT_OBJECT | SCALAR | ENUM | INTERFACE | UNION
+
+directive @goField(
+	forceResolver: Boolean
+	name: String
+) on INPUT_FIELD_DEFINITION | FIELD_DEFINITION
+
+directive @goTag(
+	key: String!
+	value: String
+) on INPUT_FIELD_DEFINITION | FIELD_DEFINITION