feat: Ability to delete account for administrators (#1874)

## Description

Add account delete option in the user account settings.

Fixes #1555 

## Type of change

- [ ] New feature (non-breaking change which adds functionality)


![image](https://user-images.githubusercontent.com/40784971/110349673-edcc5200-8058-11eb-8ded-a31d15aa0759.png)

![image](https://user-images.githubusercontent.com/40784971/110349778-0c324d80-8059-11eb-9291-abfbffedde5e.png)


## Checklist:

- [ ] My code follows the style guidelines of this project
- [ ] I have performed a self-review of my own code
- [ ] I have commented on my code, particularly in hard-to-understand
areas
- [ ] I have made corresponding changes to the documentation
- [ ] My changes generate no new warnings
- [ ] I have added tests that prove my fix is effective or that my
feature works
- [ ] New and existing unit tests pass locally with my changes
- [ ] Any dependent changes have been merged and published in downstream
modules

---------

Co-authored-by: Sojan Jose <sojan@pepalo.com>
Co-authored-by: Sojan Jose <sojan.official@gmail.com>
Co-authored-by: Muhsin Keloth <muhsinkeramam@gmail.com>

app/javascript/dashboard/api/enterprise/specs/account.spec.js

@@ -10,6 +10,7 @@ describe('#enterpriseAccountAPI', () => {
     expect(accountAPI).toHaveProperty('update');
     expect(accountAPI).toHaveProperty('delete');
     expect(accountAPI).toHaveProperty('checkout');
+    expect(accountAPI).toHaveProperty('toggleDeletion');
   });
 
   describe('API calls', () => {
@@ -42,5 +43,21 @@ describe('#enterpriseAccountAPI', () => {
         '/enterprise/api/v1/subscription'
       );
     });
+
+    it('#toggleDeletion with delete action', () => {
+      accountAPI.toggleDeletion('delete');
+      expect(axiosMock.post).toHaveBeenCalledWith(
+        '/enterprise/api/v1/toggle_deletion',
+        { action_type: 'delete' }
+      );
+    });
+
+    it('#toggleDeletion with undelete action', () => {
+      accountAPI.toggleDeletion('undelete');
+      expect(axiosMock.post).toHaveBeenCalledWith(
+        '/enterprise/api/v1/toggle_deletion',
+        { action_type: 'undelete' }
+      );
+    });
   });
 });