Feature - Oxygen builder integration

[MILAN88888]

All Submissions:

• Have you followed the Everest Forms Contributing guideline?
• Does your code follow the WordPress' coding standards?
• Have you checked to ensure there aren't other open Pull Requests for the same update/change?

Changes proposed in this Pull Request:

This PR introduces the oxygen builder integration module.
Note :- Oxygen builder zip in the jira link and install it.

How to test the changes in this Pull Request:

1. Goto dashboard > feature > oxygen > enable it.
2. Edit a page with oxygen builder > everest forms widget > drag froms
3. Choose a form and apply some style from controller.
4. Verify in editor as well as in frontend after previewing the page.

Types of changes:

• Bug fix (non-breaking change which fixes an issue)
• Enhancement (modification of the currently available functionality)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)

Other information:

• Have you added an explanation of what your changes do and why you'd like us to include them?
• Have you successfully ran tests with your changes locally?
• Have you updated the documentation accordingly?

Changelog entry

Feature - Oxygen builder integration.

[NirajChaudhary143]

LGTM 👍

[deepench]

LGTM 👍

[riteelama]

LGTM 👍

[joshianup1]

LGTM 👍