Update AppointmentsController#create method

[loripusey]

Update the AppointmentsController#create method to create the appointment in EPS. It uses the #submit_appointment method in EPS::AppointmentService. needs the appointment_id from the draft appointment call (which should already have been called in prior steps), and other parameters (network_id, provider, slot, referral etc).

AC:

• add a new route (if we decide to create a new method)
• add/update #create method
• add request specs, and VCR cassettes as needed

TBD: should we update the existing #create method, or create a new route and method for EPS specific 'create appointment' functionality.

[loripusey]

@lee-delarm6 @kanchanasuriya @randomsync this ticket needs AC

[lee-delarm6]

Appointment controller method to create draft appointment using:

/care-navigation/v1/appointments (EPS, check Swagger https://wellhive.github.io/api-docs/#/Appointment/Appointment%23create)

Which passes through to EPS service layer:

def create_draft_appointment(referral_id:)

[randomsync]

@loripusey added AC

@lee-delarm6 I believe this one is for final appointment submission. I'm working on draft functionality as part of #98249