Tim K

Add skeleton PaymentConnector.h file Add sample LNPay.cpp Basic main.ino for testing

**Describe the problem/bug** lnurl urls are not properly generated when the `callback` has a query string in it. if `request.callbackUrl=https://lnpay.co/v1/user/wallet/waka_5wtZllyHmwYqMJY5zA6kEP6/lnurl-process?ott=yolo` https://github.com/LN-Zap/zap-iOS/blob/d1d53fa8aa2690adbf3be7124e662568fc43b8d7/Lightning/LNURL/LNURL.swift#L122 generates `https://lnpay.co/v1/user/wallet/waka_5wtZllyHmwYqMJY5zA6kEP6/lnurl-process?ott=yolo?k1=123&pr=lnbc....` **To Reproduce** Steps to reproduce the behavior:...