Expose check for if ehrSupplyAuthorise is an acute prescription

[MartinWheelerMT]

What

• Added public method isAcutePrescription to check if the provided ehrSupplyPrescribe has a repeatNumber with a value of 0.
• Added unit tests for the above.

Why

So that this check can be consumed in the MedicationRequestMapper without needing to duplicate code.

Type of change

Please delete options that are not relevant.

• Internal change (non-breaking change with no effect on the functionality affecting end users)

Checklist:

• I have performed a self-review of my code
• I have made corresponding changes to the documentation
• My changes generate no new warnings
• I have added tests that prove my fix is effective or that my feature works
• New and existing unit tests pass locally with my changes
• I have updated the Changelog with details of my change in the UNRELEASED section if this change will affect end users
• A corresponding change has been made to the Mapping Documentation repository