[incubator-kie-isssues-1139] Add support for xpath in conditional paths

[elguardian]

Closes https://github.com/apache/incubator-kie-issues/issues/1139

[kie-ci3]

PR job #1 was: UNSTABLE Possible explanation: This should be test failures

Reproducer

build-chain build full_downstream -f 'https://raw.githubusercontent.com/${AUTHOR:apache}/incubator-kie-kogito-pipelines/${BRANCH:main}/.ci/buildchain-config-pr-cdb.yaml' -o 'bc' -p apache/incubator-kie-kogito-runtimes -u https://github.com/apache/incubator-kie-kogito-runtimes/pull/3493 --skipParallelCheckout

NOTE: To install the build-chain tool, please refer to https://github.com/kiegroup/github-action-build-chain#local-execution

Please look here: https://ci-builds.apache.org/job/KIE/job/kogito/job/main/job/pullrequest_jobs/job/kogito-runtimes-pr/job/PR-3493/1/display/redirect

Test results:

• PASSED: 3260
• FAILED: 1

Those are the test failures:

org.kie.kogito.codegen.tests.PublishEventIT.testExclusiveGatewayStartToEnd

expected: 2
but was: 5

[pefernan]

@elguardian From the engine side everything seems to work fine but I found an issue while testing the example in this PR inside a kogito app. Looks like there's a problem when generating the Kogito Persistence when the process variable type is org.w3c.dom.Document. The stack trace says:

java.lang.RuntimeException: io.quarkus.builder.BuildException: Build failure: Build failed due to errors
	[error]: Build step org.kie.kogito.quarkus.processes.deployment.ProcessesAssetsProcessor#postGenerationProcessing threw an exception: java.lang.RuntimeException: Error while generating proto for model class 
org.kie.kogito.hr.XPathProcessModel Custom type org.w3c.dom.Document is no supported by Kogito persistence, please consider using a class that extends java.io.Serializable and contains a no arg constructor

Additionally I couldn't make it work when the process uses a Pojo as variable, but I think we can fix this second scenario in a later improvement.

[elguardian]

@pefernan I will take care of the issue in the persistence stuff https://github.com/apache/incubator-kie-issues/issues/1204