Fix: missing 'unit_code' argument in AsyncOEClient get_facility_data method

[emvollmer]

Hello!

I noticed the AsyncOEClient.get_facility_data class method was missing the unit_code argument. Was going to create an issue but realised it would be just as quick to fix it myself and create a PR :)

Problem

Currently, the synchronous OEClient supports querying by unit_code, but the asynchronous implementation was missing this argument in its method signature, making it impossible to query specific units without hitting a 404 error when the unit code differs from the facility code.

Solution

Added the unit_code argument to AsyncOEClient.get_facility_data and updated the method where necessary to account for this change (i.e. made the facility_code optional to allow for sole use of unit_code). The changes align with the synchronous implementation.

Type of change

• Bug fix (non-breaking change which fixes an issue)

Checklist

• My code follows the style guidelines of this project
• I have performed a self-review of my code
• I have commented my code, particularly in hard-to-understand areas
• My changes generate no new warnings
• I have added tests that prove my fix is effective or that my feature works
• New and existing tests pass locally with my changes
• Any dependent changes have been merged and published in downstream modules