Enable CRM by default for new groups

What does this MR do and why?

Relates to Customer Database "for Service Desk" (or otherw... (#2256)

This MR defaults the CRM group setting to enabled for all newly created groups and subgroups.

Migrations

lee@Lees-MBP gitlab % bundle exec rails db:migrate
Attention: used pure ruby version of MurmurHash3
main: == 20230108205644 ChangeGroupCrmSettingsEnabledDefault: migrating =============
main: -- change_column_default(:group_crm_settings, :enabled, {:from=>false, :to=>true})
main:    -> 0.0723s
main: == 20230108205644 ChangeGroupCrmSettingsEnabledDefault: migrated (0.0783s) ====

lee@Lees-MBP gitlab % bundle exec rails db:migrate:down VERSION=20230108205644
Attention: used pure ruby version of MurmurHash3
main: == 20230108205644 ChangeGroupCrmSettingsEnabledDefault: reverting =============
main: -- change_column_default(:group_crm_settings, :enabled, {:from=>true, :to=>false})
main:    -> 0.0748s
main: == 20230108205644 ChangeGroupCrmSettingsEnabledDefault: reverted (0.0794s) ====

How to set up and validate locally

https://docs.gitlab.com/ee/user/crm/

1. Create a new root group
2. Ensure the CRM option is enabled https://docs.gitlab.com/ee/user/crm/#enable-customer-relations-management-crm
3. Ensure the customer relations > contacts and organizations left navigation menu/sidebar options appear
4. Create a subgroup
5. Ensure the CRM option is enabled

MR acceptance checklist

This checklist encourages us to confirm any changes have been analyzed to reduce risks in quality, performance, reliability, security, and maintainability.

• I have evaluated the MR acceptance checklist for this MR.

Related to #2256

app/models/group.rb

@@ -160,7 +160,6 @@ def of_ancestors_and_self
 
   after_create :post_create_hook
   after_create -> { create_or_load_association(:group_feature) }
-  after_create -> { create_or_load_association(:crm_settings) }
   after_update :path_changed_hook, if: :saved_change_to_path?
   after_destroy :post_destroy_hook
   after_commit :update_two_factor_requirement
@@ -886,7 +885,7 @@ def group_feature
   end
 
   def crm_enabled?
-    crm_settings&.enabled?
+    crm_settings.nil? || crm_settings.enabled?
   end
 
   def shared_with_group_links_visible_to_user(user)