Replace Kogito-examples group-id from 'org.kie.kogito.example' to 'org.acme'

We can change the group-id of each example in the Kogito-examples repo to use `org.acme`, since we are not planning to deploy the examples to maven.

Some examples are using `org.acme` group-id, These should be changed to `org.kie.kogito` to keep the consistency in the examples.

We can change the group-id of each example in the Kogito-examples repo to use `org.acme`, so it won't clash with our name spaces. 
As discussed, we should update our contribution guidelines on how should we name group-ids based on code/project.

> org.acme -> examples, tutorials, quickstarts, any user-facing projects with this intention.
> org.kie.kogito -> our core projects

In addition to the renaming work, we also need to remove any parent pom from the examples to get each example working as standalone, so it can be easily installed anywhere.