Improve serverless-workflow-examples-parent structure

[tkobayas]

Description

#1987 (comment)
#1987 (comment)
serverless-workflow-examples-parent is a sibling of other modules. The parent module falls out of the reactor if default profile is not used.

If the structure will be the same as quarkus / springboot examples, mvnVersionsSet in #1987 may not be required.

Implementation ideas

No response