ref(doc): updated GIG DNS API swagger doc

[QiluXie]

Problem

Closes IS-812

The GIG DNS API swagger doc is outdated with a few new incoming requirements from GIG team.

Solution

Updated the API swagger doc to reflect the latest requirements from GIG team:

• Added PUT call to the API suite for updating DNS records
• Added an optional field rootDomain to PUT and POST calls in the request body
• Added an optional query parameter rootDomain and a required parameter email to DELETE call

Breaking Changes

• Yes - this PR contains breaking changes
  • Details ...
• No - this PR is backwards compatible with ALL of the following feature flags in this doc

Improvements:

• Updated the API swagger doc to reflect the latest requirements from GIG team.

Before & After Screenshots

AFTER:

• The swagger file can be loaded manually on swagger.io

Tests

• The swagger file can be loaded manually on swagger.io