Merge branch '18755-fix-destroy-project-causes-post_decline_request-to-be-executed' into 'master'

Resolve "Destroying a project causes post_decline_request to be executed"

## What does this MR do?

Ensure we don't send "access request declined" to access requesters when a project is deleted.

## Are there points in the code the reviewer needs to double check?

I've created a service to decouple the notification sending from the AR model.

## Why was this MR needed?

Because there was an issue.

## What are the relevant issue numbers?

Fixes #18755, #18750.

## Does this MR meet the acceptance criteria?

- [x] No CHANGELOG needed.
- [x] Tests
  - [x] Added for this feature/bug
  - [x] All builds are passing
- [x] Conform by the [style guides](https://gitlab.com/gitlab-org/gitlab-ce/blob/master/CONTRIBUTING.md#style-guides)
- [x] Branch has no merge conflicts with `master` (if you do - rebase it please)
- [x] [Squashed related commits together](https://git-scm.com/book/en/Git-Tools-Rewriting-History#Squashing-Commits)

See merge request !4744

1 files changed, 0 insertions, 42 deletions

diff --git a/features/steps/dashboard/group.rb b/features/steps/dashboard/group.rb
index 9b79a3be49b..cf679fea530 100644
--- a/features/steps/dashboard/group.rb
+++ b/features/steps/dashboard/group.rb
@@ -4,44 +4,6 @@ class Spinach::Features::DashboardGroup < Spinach::FeatureSteps
   include SharedPaths
   include SharedUser
 
-  # Leave
-
-  step 'I click on the "Leave" button for group "Owned"' do
-    find(:css, 'li', text: "Owner").find(:css, 'i.fa.fa-sign-out').click
-    # poltergeist always confirms popups.
-  end
-
-  step 'I click on the "Leave" button for group "Guest"' do
-    find(:css, 'li', text: "Guest").find(:css, 'i.fa.fa-sign-out').click
-    # poltergeist always confirms popups.
-  end
-
-  step 'I should not see the "Leave" button for group "Owned"' do
-    expect(find(:css, 'li', text: "Owner")).not_to have_selector(:css, 'i.fa.fa-sign-out')
-    # poltergeist always confirms popups.
-  end
-
-  step 'I should not see the "Leave" button for groupr "Guest"' do
-    expect(find(:css, 'li', text: "Guest")).not_to have_selector(:css,  'i.fa.fa-sign-out')
-    # poltergeist always confirms popups.
-  end
-
-  step 'I should see group "Owned" in group list' do
-    expect(page).to have_content("Owned")
-  end
-
-  step 'I should not see group "Owned" in group list' do
-    expect(page).not_to have_content("Owned")
-  end
-
-  step 'I should see group "Guest" in group list' do
-    expect(page).to have_content("Guest")
-  end
-
-  step 'I should not see group "Guest" in group list' do
-    expect(page).not_to have_content("Guest")
-  end
-
   step 'I click new group link' do
     click_link "New Group"
   end
@@ -60,8 +22,4 @@ class Spinach::Features::DashboardGroup < Spinach::FeatureSteps
     expect(page).to have_content "Samurai"
     expect(page).to have_content "Tokugawa Shogunate"
   end
-
-  step 'I should see the "Can not leave message"' do
-    expect(page).to have_content "You can not leave the \"Owned\" group."
-  end
 end