Add Airlabs integration for flight schedules and details; update vers…

[WickedGhost]

This pull request introduces a new opt-in "Airlabs schedules" mode, allowing the integration to fetch and normalize flight schedules from Airlabs for airports that are missing or incomplete in Avinor's public feed. It also adds configuration options for selecting the schedule source and improves Airlabs API key handling and documentation. Several internal changes support deduplication and normalization of Airlabs data to match the existing sensor format.

New Airlabs schedules support:

• Added a Schedule source option (avinor or airlabs) to the configuration flow and sensor options, allowing users to select Airlabs as a data source for schedules. [1] [2] [3] [4]
• Implemented Airlabs schedules fetching, deduplication of codeshare flights, and normalization of Airlabs data to the sensor format in AirlabsApiClient (api.py).
• Updated the coordinator to use Airlabs schedules when selected, passing appropriate parameters and handling the Airlabs API key.

Documentation and user experience:

• Updated README.md to document the new schedule source option, explain Airlabs API key usage, and provide release notes for versions 1.1.0 and 1.1.1. [1] [2] [3] [4]
• Improved config wizard translations for the Airlabs API key field so the explanatory text is picked up correctly.

Other improvements and housekeeping:

• Bumped the version to 1.1.1 in both manifest.json and README.md. [1] [2]
• Added new Airlabs API endpoints and constants to const.py to support the schedules and airports APIs.
• Refactored internal API and coordinator logic to support the new features and configuration options. [1] [2] [3]

These changes make the integration more robust for airports with incomplete Avinor data and improve the overall configuration and documentation experience.…ion to 1.1.1