Add read_merge_request to gql project permission

**Why?**

This is needed to support the IDE working for projects
without Merge Requests

app/graphql/types/permission_types/project.rb

@@ -16,7 +16,8 @@ module Types
                 :create_deployment, :push_to_delete_protected_branch,
                 :admin_wiki, :admin_project, :update_pages,
                 :admin_remote_mirror, :create_label, :update_wiki, :destroy_wiki,
-                :create_pages, :destroy_pages, :read_pages_content, :admin_operations
+                :create_pages, :destroy_pages, :read_pages_content, :admin_operations,
+                :read_merge_request
 
       permission_field :create_snippet
 

doc/api/graphql/reference/gitlab_schema.graphql

@@ -5831,6 +5831,11 @@ type ProjectPermissions {
   """
   readDesign: Boolean!
 
+  """
+  Indicates the user can perform `read_merge_request` on this resource
+  """
+  readMergeRequest: Boolean!
+
   """
   Indicates the user can perform `read_pages_content` on this resource
   """

doc/api/graphql/reference/gitlab_schema.json

@@ -2253,6 +2253,24 @@
               "isDeprecated": false,
               "deprecationReason": null
             },
+            {
+              "name": "readMergeRequest",
+              "description": "Indicates the user can perform `read_merge_request` on this resource",
+              "args": [
+
+              ],
+              "type": {
+                "kind": "NON_NULL",
+                "name": null,
+                "ofType": {
+                  "kind": "SCALAR",
+                  "name": "Boolean",
+                  "ofType": null
+                }
+              },
+              "isDeprecated": false,
+              "deprecationReason": null
+            },
             {
               "name": "readPagesContent",
               "description": "Indicates the user can perform `read_pages_content` on this resource",

doc/api/graphql/reference/index.md

@@ -867,6 +867,7 @@ Information about pagination in a connection.
 | `readCommitStatus` | Boolean! | Indicates the user can perform `read_commit_status` on this resource |
 | `readCycleAnalytics` | Boolean! | Indicates the user can perform `read_cycle_analytics` on this resource |
 | `readDesign` | Boolean! | Indicates the user can perform `read_design` on this resource |
+| `readMergeRequest` | Boolean! | Indicates the user can perform `read_merge_request` on this resource |
 | `readPagesContent` | Boolean! | Indicates the user can perform `read_pages_content` on this resource |
 | `readProject` | Boolean! | Indicates the user can perform `read_project` on this resource |
 | `readProjectMember` | Boolean! | Indicates the user can perform `read_project_member` on this resource |

spec/graphql/types/permission_types/project_spec.rb

@@ -12,7 +12,8 @@ describe Types::PermissionTypes::Project do
       :read_commit_status, :request_access, :create_pipeline, :create_pipeline_schedule,
       :create_merge_request_from, :create_wiki, :push_code, :create_deployment, :push_to_delete_protected_branch,
       :admin_wiki, :admin_project, :update_pages, :admin_remote_mirror, :create_label,
-      :update_wiki, :destroy_wiki, :create_pages, :destroy_pages, :read_pages_content
+      :update_wiki, :destroy_wiki, :create_pages, :destroy_pages, :read_pages_content,
+      :read_merge_request
     ]
 
     expected_permissions.each do |permission|