Use camel test for running integration tests instead of citrus cli

[davsclaus]

such as openapi example, but there may be others that need to update their readme instructions

@christophd

[christophd]

Just an update to this one. I did some improvements in Citrus that help us to use Camel test plugin effectively for this purpose. Let's wait for Camel 4.18.1 and use it then