Draft: Add rubocop-graphql enabling all bundled cop rules

What does this MR do and why?

Sneak preview of https://gitlab.com/gitlab-org/gitlab-styles/-/merge_requests/95.

Let's see how https://gitlab.com/gitlab-org/gitlab/-/jobs/1748279921 goes.

🆕 👮

--- before	2021-11-04 14:20:11.404375749 +0100
+++ after	2021-11-04 14:20:19.464747793 +0100
@@ -1,4 +1,4 @@
-# Available cops (797) + config for /home/peter/devel/gitlab/gdk-ee/gitlab: 
+# Available cops (811) + config for /home/peter/devel/gitlab/gdk-ee/gitlab: 
 # Department 'API' (2):
 # Supports --auto-correct
 API/Base:
@@ -527,6 +527,98 @@
   - "/home/peter/devel/gitlab/gdk-ee/gitlab/lib/**/*.rake"
   - "/home/peter/devel/gitlab/gdk-ee/gitlab/spec/**/*"
 
+# Department 'GraphQL' (14):
+GraphQL/ArgumentDescription:
+  Enabled: true
+  VersionAdded: '0.80'
+  Description: Ensures all arguments have a description
+
+GraphQL/ArgumentName:
+  Enabled: true
+  VersionAdded: '0.80'
+  Description: This cop checks whether argument names are snake_case
+
+GraphQL/ExtractInputType:
+  Enabled: true
+  VersionAdded: '0.80'
+  Description: Suggests using input type instead of many arguments
+  MaxArguments: 2
+
+GraphQL/ExtractType:
+  Enabled: true
+  VersionAdded: '0.80'
+  Description: Suggests extracting fields with common prefixes to the separate type
+  MaxFields: 2
+  Prefixes:
+  - is
+  - with
+  - avg
+  - min
+  - max
+
+# Supports --auto-correct
+GraphQL/FieldDefinitions:
+  Enabled: true
+  VersionAdded: '0.80'
+  Description: Checks consistency of field definitions
+  EnforcedStyle: group_definitions
+  SupportedStyles:
+  - group_definitions
+  - define_resolver_after_definition
+
+GraphQL/FieldDescription:
+  Enabled: true
+  VersionAdded: '0.80'
+  Description: Ensures all fields have a description
+
+# Supports --auto-correct
+GraphQL/FieldHashKey:
+  Enabled: true
+  VersionAdded: '0.80'
+  Description: Checks :hash_key option is used for appropriate fields
+
+# Supports --auto-correct
+GraphQL/FieldMethod:
+  Enabled: true
+  VersionAdded: '0.80'
+  Description: Checks :method option is used for appropriate fields
+
+# Supports --auto-correct
+GraphQL/FieldName:
+  Enabled: true
+  VersionAdded: '0.80'
+  Description: This cop checks whether field names are snake_case
+  SafeAutoCorrect: false
+
+GraphQL/LegacyDsl:
+  Enabled: true
+  VersionAdded: '0.80'
+  Description: Checks that types are defined with class-based API
+
+GraphQL/ObjectDescription:
+  Enabled: true
+  VersionAdded: '0.80'
+  Description: Ensures all types have a description
+  Exclude:
+  - "/home/peter/devel/gitlab/gdk-ee/gitlab/**/*_schema.rb"
+  - "/home/peter/devel/gitlab/gdk-ee/gitlab/**/base_*.rb"
+
+# Supports --auto-correct
+GraphQL/OrderedArguments:
+  Enabled: true
+
+# Supports --auto-correct
+GraphQL/OrderedFields:
+  Enabled: true
+
+GraphQL/ResolverMethodLength:
+  Enabled: true
+  VersionAdded: '0.80'
+  Description: Checks resolver methods are not too long
+  Max: 10
+  CountComments: false
+  ExcludedMethods: []
+
 # Department 'Graphql' (7):
 Graphql/AuthorizeTypes:
   Enabled: true

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