weld: Move weld::Image to own header

Move the class out of weld.hxx into its own header, in
order to make it easier to keep an overview and to avoid
having to recompile ~all UI code when the class is
modified.

Change-Id: I2eb564b2483b052f01d4af55fd4feb00b5ed6031
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/205472
Reviewed-by: Michael Weghorn <m.weghorn@posteo.de>
Tested-by: Jenkins

xmlsecurity/inc/certificateviewer.hxx

@@ -22,6 +22,7 @@
 #include <utility>
 #include <vcl/weld/Builder.hxx>
 #include <vcl/weld/DialogController.hxx>
+#include <vcl/weld/Image.hxx>
 #include <vcl/weld/Notebook.hxx>
 #include <vcl/weld/TextView.hxx>
 #include <vcl/weld/TreeView.hxx>

xmlsecurity/inc/digitalsignaturesdialog.hxx

@@ -20,6 +20,7 @@
 #pragma once
 
 #include <vcl/weld/DialogController.hxx>
+#include <vcl/weld/Image.hxx>
 #include <vcl/weld/TreeView.hxx>
 #include <vcl/weld/Window.hxx>
 #include <vcl/weld/weld.hxx>

xmlsecurity/inc/macrosecurity.hxx

@@ -21,6 +21,7 @@
 
 #include <vcl/weld/Builder.hxx>
 #include <vcl/weld/DialogController.hxx>
+#include <vcl/weld/Image.hxx>
 #include <vcl/weld/Notebook.hxx>
 #include <vcl/weld/TreeView.hxx>
 #include <vcl/weld/weld.hxx>