[Integration][async-gitlab] - GitLab integration with Async support

[victor-devv]

Description

What - Ocean Gitlab integration with async support using the http async client. Includes support for resources which includes groups, projects, merge requests and issues; as well as webhooks.

Why -

How -

Type of change

Please leave one option from the following and delete the rest:

• New Integration (non-breaking change which adds a new integration)

All tests should be run against the port production environment(using a testing org).

Core testing checklist

• Integration able to create all default resources from scratch
• Resync finishes successfully
• Resync able to create entities
• Resync able to update entities
• Resync able to detect and delete entities
• Scheduled resync able to abort existing resync and start a new one
• Tested with at least 2 integrations from scratch
• Tested with Kafka and Polling event listeners
• Tested deletion of entities that don't pass the selector

Integration testing checklist

• Integration able to create all default resources from scratch
• Resync able to create entities
• Resync able to update entities
• Resync able to detect and delete entities
• Resync finishes successfully
• If new resource kind is added or updated in the integration, add example raw data, mapping and expected result to the examples folder in the integration directory.
• If resource kind is updated, run the integration with the example data and check if the expected result is achieved
• If new resource kind is added or updated, validate that live-events for that resource are working as expected
• Docs PR link here

Preflight checklist

• Handled rate limiting
• Handled pagination
• Implemented the code in async
• Support Multi account

Screenshots

API Documentation

Provide links to the API documentation used for this integration.

[kodjomiles]

why is lead time a calculation property here, The calculation should be done in the mapping configuration and default to null if the pr hasn't been merged. we have access to both mergedAt and createdAt at the time of ingesting. this would help the reuse of leadTime. calculation properties are done on the fly. there are instances that we need to use leadTime.