Move all EE lib differences to EE specific modules

EE specific code that resides in lib should be moved to corresponding EE specific modules that reside in ee/lib, leaving behind only the necessary prepend and include calls, which should be placed at the end of the file).

Differences

These differences take into account the following MRs:

• https://gitlab.com/gitlab-org/gitlab-ee/merge_requests/10326
• https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/26369

lib/gitlab/import_export/import_export.yml: moved to https://gitlab.com/gitlab-org/gitlab-ee/issues/6524

diff --git a/lib/gitlab/import_export/import_export.yml b/home/yorickpeterse/Projects/gitlab/gdk-ee/gitlab/lib/gitlab/import_export/import_export.yml
index ce268793128..03ccb857cbf 100644
--- a/lib/gitlab/import_export/import_export.yml
+++ b/home/yorickpeterse/Projects/gitlab/gdk-ee/gitlab/lib/gitlab/import_export/import_export.yml
@@ -67,6 +67,9 @@ project_tree:
   - protected_branches:
     - :merge_access_levels
     - :push_access_levels
+    - :unprotect_access_levels
+  - protected_environments:
+    - :deploy_access_levels
   - protected_tags:
     - :create_access_levels
   - :project_feature
@@ -113,10 +116,18 @@ excluded_attributes:
     - :last_activity_at
     - :last_repository_updated_at
     - :last_repository_check_at
+    - :mirror_user_id
+    - :mirror_trigger_builds
     - :storage_version
     - :remote_mirror_available_overridden
+    - :only_mirror_protected_branches
+    - :pull_mirror_available_overridden
+    - :mirror_overwrites_diverged_branches
     - :description_html
     - :repository_languages
+    - :packages_enabled
+    - :mirror_last_update_at
+    - :mirror_last_successful_update_at
     - :bfg_object_map
     - :detected_repository_languages
     - :tag_list
@@ -126,6 +137,8 @@ excluded_attributes:
   project_import_state:
     - :last_error
     - :jid
+    - :last_update_at
+    - :last_successful_update_at
   prometheus_metrics:
     - :common
     - :identifier