Improvement of polling disabled mode
Improvement of polling disabled mode

Improvement of work for callbacks mechanism in cases when polling is off.  Refactoring aim to make mechanism more simple and remove current bugs.

Main changes:
* Always send notification url.
* Do not parse callbacks base on method and device type.
* Always process backurl calls
* Get all information from url params
SeamlessDistribution/woocommerce-seqr-payment-gateway,SeamlessDistribution/woocommerce-seqr-payment-gateway