CppTools: Rename SnapshotUpdater to BuiltinEditorDocumentParser

Change-Id: I554b5e9e3f1ef7c167fa45b5cd0c230fdf63073b
Reviewed-by: Erik Verbruggen <erik.verbruggen@digia.com>
CppTools: Denoise with BuiltinEditorDocumentParser::Ptr

Change-Id: I1d572e8cc3e76ef6bbae720e3c3482292aab9609
Reviewed-by: Erik Verbruggen <erik.verbruggen@digia.com>
CppEditor: Remove CppEditorWidget dependency of CanonicalSymbol

Change-Id: I3c42d9df93756d9f85682465b9661d7e75ffa71e
Reviewed-by: Erik Verbruggen <erik.verbruggen@digia.com>