Utils: Centralize aspect macro expansion setup and handling

Let each aspect have a macro expander, and let aspect-owned lineedits
use this for expansion.

Change-Id: Ifa6f5a678cf81c169643e4145f41e69eafedeb93
Reviewed-by: Marcus Tillmanns <marcus.tillmanns@qt.io>

src/plugins/projectexplorer/workspaceproject.cpp

@@ -180,8 +180,6 @@ public:
         executable.setLabelText(Tr::tr("Executable:"));
         executable.setReadOnly(true);
         executable.setValue(bti.targetFilePath);
-        executable.setMacroExpanderProvider(
-            [this]() -> MacroExpander * { return const_cast<MacroExpander *>(macroExpander()); });
 
         auto argumentsAsString = [this]() {
             return CommandLine{