feat: Added Iterable Connector

[TivonB-AI2]

Description

Add Iterable Connector

Related Issue

https://linear.app/ai-squared/issue/OSS-3/iterable-destination-connector

Type of Change

• [ ] Bug fix (non-breaking change which fixes an issue)
• [ ] New feature (non-breaking change which adds functionality)
• [x] New Connector (Destination or Source Connector)
• [ ] Breaking change (fix or feature that would impact existing functionality)
• [ ] Styling change
• [ ] Documentation update
• [ ] Refactoring
• [ ] Chore

How Has This Been Tested?

Rspec unit test

Checklist:

• [x] Ensure a branch name is prefixed with feature, bugfix, hotfix, release, style or chore followed by / and branch name e.g feature/add-salesforce-connector
• [x] Added unit tests for the changes made (if required)
• [ ] Have you made sure the commit messages meets the guidelines?
• [ ] Added relevant screenshots for the changes
• [x] Have you tested the changes on local/staging?
• [x] Added the new connector in rollout.rb
• [ ] Have you updated the version number of the gem?
• [ ] Have you ensured that your changes for new connector are documented in the docs repo or relevant documentation files?
• [ ] Have you updated the run time dependency in multiwoven-integrations.gemspec if new gems are added
• [ ] Have you made sure the code you have written follows the best practises to the best of your knowledge?