feat: Add company model and API with tests (#12548)

# Pull Request Template

## Description

* add Company model with validations for name, domain, description and
  avatar
* Add database migration fo
* Implement endpoints for company CRUD operations
* Add optional company relationship for contacts
* Add test for models, controllers, factories and policies
* Add authorization policies restricting delete to admins
* support JSON API responses
Please include a summary of the change and issue(s) fixed. Also, mention
relevant motivation, context, and any dependencies that this change
requires.

Fixes #(cw-5650)

## Type of change

Please delete options that are not relevant.

- [x] Bug fix (non-breaking change which fixes an issue)
- [ ] New feature (non-breaking change which adds functionality)
- [ ] Breaking change (fix or feature that would cause existing
functionality not to work as expected)
- [ ] This change requires a documentation update

## How Has This Been Tested?

Tests are implemented using `RSpec`

```
$ bundle exec rails db:migrate
$ bundle exec rspec spec/models/company_spec.rb spec/controllers/api/v1/accounts/companies_controller_spec.rb
```

## Checklist:

- [x] My code follows the style guidelines of this project
- [x] I have performed a self-review of my code
- [x] I have commented on my code, particularly in hard-to-understand
areas
- [ ] I have made corresponding changes to the documentation
- [x] My changes generate no new warnings
- [x] 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

app/models/user.rb

@@ -19,7 +19,7 @@
 #  message_signature      :text
 #  name                   :string           not null
 #  otp_backup_codes       :text
-#  otp_required_for_login :boolean          default(FALSE), not null
+#  otp_required_for_login :boolean          default(FALSE)
 #  otp_secret             :string
 #  provider               :string           default("email"), not null
 #  pubsub_token           :string