feat: Add validation of entities to `breezy-hr` maps

[martinalbert]

Description

Adds operations for checking availability of entities needed to perform the use case.

Motivation and Context

Breezy-hr returns in most endpoints only 400, 401 and other errors as 500.

Types of changes

• [ ] Bug fix (non-breaking change which fixes an issue)
• [ ] New feature (non-breaking change which adds functionality)
• [ ] Breaking change (fix or feature that would cause existing functionality to change)

Checklist:

• [ ] I have read the CONTRIBUTING document.
• [ ] I haven't repeated the code. (DRY)
• [ ] I have added tests to cover my changes.
• [ ] All new and existing tests passed.

[martinalbert]

@janhalama workable also doesn't offer much detail into what is missing, should I open similar PR for validation of entities in workable?

[janhalama]

@janhalama workable also doesn't offer much detail into what is missing, should I open similar PR for validation of entities in workable?

Yes that would be great.

[martinalbert]

@janhalama added missing tests and opened new PR built on top of this one for validation of entities in workable maps.