Validate customer or seller registration when running in REST and CLI environments

[ediamin]

Dokan is using Dokan_Registration::validate_registration to validate customer and seller registration process only when in browser environment(ie, only when we have $_POST present). We need to validate this process in REST and CLI environment too.

[DastanIqbal]

After applying this fix also,I cannot call http://exmple.com/wp-json/dokan/v1/user/register. I checked http://exmple.com/wp-json/ there is no route dokan/v1/user/register. Instead I am getting this response when I am posting

{"code":"rest_no_route","message":"No route was found matching the URL and request method","data":{"status":404}}

Please help. !!