Add OpenAPI task implementation

[fjtirado]

Implement OpenAPI task.

@mcruzdev Take a look to https://github.com/serverlessworkflow/sdk-java/blob/main/impl/http/src/main/java/io/serverlessworkflow/impl/executors/HttpExecutor.java
There should be a new maven module that follow the same approach for OpenAPI

[mcruzdev]

This one is very interesting, I would like to contribute with.