Grails 3: detached criteria AST transformation support

Completion of fields, navigation, resolve.

Before Grails 3:
```
def query = Person.withCritera {
or {
and {
ne 'lastName', 'Simpson'
ne 'firstName', 'Fred'
}
and {
​
eq 'firstname', "Bart"
gt 'age', 9
}

}
}
```
Now it is possible to write as:
```
def query = Person.where {
(lastName != "Simpson" && firstName != "Fred") || (firstName == "Bart" && age > 9)
}
```

---

*Imported from [IDEA-145856](https://youtrack.jetbrains.com/issue/IDEA-145856) · Type: Bug · Votes: 2*
*Comments, attachments, dates and reporter are not part of the export — follow the link above for the full history.*

No source file or test is named. Start by locating the Grails 3 detached criteria AST transformation support and compare it with existing `where` support; verify completion, field navigation, and resolve for the example expressions when done.

Written by the indexing model from the issue text.