Remove read-only attributes from posts mutations

For the comments, the fix is not that easy: They are still using
`neo4j-graphql-js` in the resolvers. And that library needs the input
params for the query builder.

See: https://github.com/Human-Connection/Human-Connection/issues/1454

backend/src/middleware/softDeleteMiddleware.spec.js

@@ -17,7 +17,7 @@ let user
 let moderator
 let troll
 
-let action = () => {
+const action = () => {
   return query({ query: graphqlQuery })
 }
 

backend/src/schema/resolvers/posts.js

@@ -108,7 +108,7 @@ export default {
       params = await fileUpload(params, { file: 'imageUpload', url: 'image' })
       const session = context.driver.session()
 
-      let updatePostCypher = `MATCH (post:Post {id: $params.id}) 
+      let updatePostCypher = `MATCH (post:Post {id: $params.id})
       SET post = $params
       `
 

backend/src/schema/types/type/Post.gql

@@ -57,26 +57,18 @@ type Post {
 type Mutation {
   CreatePost(
     id: ID
-    activityId: String
-    objectId: String
     title: String!
     slug: String
     content: String!
     image: String
     imageUpload: Upload
     visibility: Visibility
-    deleted: Boolean
-    disabled: Boolean
-    createdAt: String
-    updatedAt: String
     language: String
     categoryIds: [ID]
     contentExcerpt: String
   ): Post
   UpdatePost(
     id: ID!
-    activityId: String
-    objectId: String
     title: String!
     slug: String
     content: String!
@@ -84,10 +76,6 @@ type Mutation {
     image: String
     imageUpload: Upload
     visibility: Visibility
-    deleted: Boolean
-    disabled: Boolean
-    createdAt: String
-    updatedAt: String
     language: String
     categoryIds: [ID]
   ): Post