Improve query operation for nested child resources

This is another similar RFE as WFCORE-2041.

It would be good if the 'query()' operation can filter the resources by specifying value of attributes which are inside of nested child resources(not only by the first level of child resource), so that, for example, the following command can work well as expected:

[standalone@localhost:9990 /] /subsystem=security:query(select=[security-domain], where={security-domain.authentication.login-modules.code=RealmDirect})
{
    "outcome" => "success",
    "result" => undefined
}
// here the expected output are the security-domain resources which have the loging-module RealmDirect defined.

The security-domain.authentication.login-modules.code in 'where' parameter is proposed attribute name in enhanced syntax, other options maybe possible.

The different requirements between this WFCORE-2042 and WFCORE-2041 are:

• WFCORE-2041 focus on complex attributes in one management resource
• WFCORE-2042 focus on nested management resources with or without complex attributes