qmljs: add infrastructure handling qml dialects better

QmlBundles enables us to treat the different qml
dialects differently.

Add imports completion.

Change-log: [Qml/JS Support] Corrected handling of QtQuick2 only features.
Change-log: [Qml/JS Support] Added import completion in editor.
Task-number: QTCREATORBUG-8750
Task-number: QTCREATORBUG-8624
Task-number: QTCREATORBUG-8584
Task-number: QTCREATORBUG-8583
Task-number: QTCREATORBUG-8429

Change-Id: I1384b1b23136a85b4d077895ea86f92960da9e71
Reviewed-by: Kai Koehne <kai.koehne@digia.com>

src/libs/qmljs/qmljs.qbs

@@ -23,6 +23,8 @@ QtcLibrary {
         "qmljs_global.h",
         "qmljsbind.cpp",
         "qmljsbind.h",
+        "qmljsbundle.cpp",
+        "qmljsbundle.h",
         "qmljscheck.cpp",
         "qmljscheck.h",
         "qmljscodeformatter.cpp",