Doctor Finder - App de Reservación de Citas con Horario 13.0

1) AI Powered chat is included (Google Gemini)

1) Added Stripe gateway to pay appointment fees
2) Added Stripe gateway to pay subscription by doctors

1) Prescription and Medical Reports
- Doctor can add Medicine for patient
- Doctor can add Reports of patient
- Medicine and reports is saved electronically in system

1) Add firebase chat between patient and doctor
2) Add video calling for online consultation

1) update flutter & Dart version
-> Flutter : 3.7.7
-> Dart : 2.19.4