Identify the service by URL

[jiw-mh]

Function URLs for lambdas look like: {function}.lambda-url.{region}.on.aws. To execute it the service needs to be lambda and the region needs to be set. Instead of using --region {region} --service lambda ... it seems like awscurl could identify that the default service for a .on.aws url is lambda and take the {region} out of the url as well.

[okigan]

@jiw-mh it probably could work, I'd happy to have a look if you'd make a PR proposal.