QmlDesigner: Unify texture image providers

Texture editor, material browser, and UrlChooser all had separate
texture providers that served nearly identical purpose.
Unified all use cases to use same PropertyEditorImageProvider.
This provider is asynchronous, which combined with enabling caching on
Image elements, significantly improves responsiveness of the material
browser UI when there are many textures shown in the browser.

Fixes: QDS-8387
Change-Id: I2888aee2f4320dba9456fa046c9ede319673a3d9
Reviewed-by: Mahmoud Badri <mahmoud.badri@qt.io>

src/plugins/qmldesigner/components/textureeditor/textureeditorcontextobject.h

@@ -73,6 +73,7 @@ public:
 
     Q_INVOKABLE bool isBlocked(const QString &propName) const;
     Q_INVOKABLE void goIntoComponent();
+    Q_INVOKABLE QString resolveResourcePath(const QString &path);
 
     enum ToolBarAction {
         ApplyToSelected,