[WFCORE-5343]: YAML support for configuration customization.

[ehsavoie]

Disabled by default experimental feature

• filtering elements to be processed
• moving logs to debug
• adding some perfs traces
• Multi file support
• Adding support for ignoring some elements
• Adding tags to support:
  • deleting a resource
  • undefining an attribute
  • list-add with index support
• trying to be smart to detect cli scripts application to set InteractionPolicy
• support reloading
• Adding support for multiple defintion of the same key.
• Adding support for flattening YAML
• Making the YAML support easily removable

Jira: https://issues.redhat.com/browse/WFCORE-5343

[wildfly-ci]

Core - Full Integration Build 11048 outcome was FAILURE using a merge of e952a7a
Summary: Tests failed: 1 (1 new), passed: 7157, ignored: 136 Build time: 04:10:49

Failed tests

org.wildfly.test.scripts.WsConsumeScriptTestCase: java.io.UncheckedIOException: java.nio.file.FileSystemException: /store/work/tc-work/ce8f2f3320903e86/full/testsuite/scripts/target/wildfly/bin/client/jboss-cli-client.jar -> /store/work/tc-work/ce8f2f3320903e86/full/testsuite/scripts/target/wildfly core/bin/client/jboss-cli-client.jar: No space left on device
	at org.wildfly.test.common.ServerConfigurator.copy(ServerConfigurator.java:60)
	at org.wildfly.test.common.ServerConfigurator.configure(ServerConfigurator.java:46)
	at org.wildfly.test.scripts.ScriptTestCase.configureEnvironment(ScriptTestCase.java:74)
Caused by: java.nio.file.FileSystemException: /store/work/tc-work/ce8f2f3320903e86/full/testsuite/scripts/target/wildfly/bin/client/jboss-cli-client.jar -> /store/work/tc-work/ce8f2f3320903e86/full/testsuite/scripts/target/wildfly core/bin/client/jboss-cli-client.jar: No space left on device
	at sun.nio.fs.UnixException.translateToIOException(UnixException.java:91)
	at sun.nio.fs.UnixException.rethrowAsIOException(UnixException.java:102)
	at sun.nio.fs.UnixCopyFile.copyFile(UnixCopyFile.java:253)
	at sun.nio.fs.UnixCopyFile.copy(UnixCopyFile.java:581)
	at sun.nio.fs.UnixFileSystemProvider.copy(UnixFileSystemProvider.java:253)
	at java.nio.file.Files.copy(Files.java:1274)
	at org.wildfly.test.common.ServerConfigurator$1.visitFile(ServerConfigurator.java:76)
	at org.wildfly.test.common.ServerConfigurator$1.visitFile(ServerConfigurator.java:65)
	at java.nio.file.Files.walkFileTree(Files.java:2670)
	at java.nio.file.Files.walkFileTree(Files.java:2742)
	at org.wildfly.test.common.ServerConfigurator.copyDirectory(ServerConfigurator.java:65)
	at org.wildfly.test.common.ServerConfigurator.copy(ServerConfigurator.java:57)
	... 21 more

[jmesnil]

For the record, usually, we don't accept such big patch in WildFly Core micro releases (that typically includes bug fixes and component upgrades only.
But this feature is experimental, well-contained and disabled by default, so I'm fine with incorporating in the upcoming 18.0.3.Final release