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/views/api/v1/models/_account.json.jbuilder

@@ -11,6 +11,10 @@ if resource.custom_attributes.present?
     json.timezone resource.custom_attributes['timezone'] if resource.custom_attributes['timezone'].present?
     json.logo resource.custom_attributes['logo'] if resource.custom_attributes['logo'].present?
     json.onboarding_step resource.custom_attributes['onboarding_step'] if resource.custom_attributes['onboarding_step'].present?
+    json.marked_for_deletion_at resource.custom_attributes['marked_for_deletion_at'] if resource.custom_attributes['marked_for_deletion_at'].present?
+    if resource.custom_attributes['marked_for_deletion_reason'].present?
+      json.marked_for_deletion_reason resource.custom_attributes['marked_for_deletion_reason']
+    end
   end
 end
 json.domain @account.domain