Utils: Temporarily introdce Key Id::toKey()

To avoid complications on the user code side during the Key/Store
transition.

Change-Id: I49ae9d496c9c1ee07f17245616fdefefe9abfc2e
Reviewed-by: Marcus Tillmanns <marcus.tillmanns@qt.io>
Reviewed-by: <github-actions-qt-creator@cristianadam.eu>

src/libs/utils/id.cpp

@@ -158,6 +158,16 @@ QString Id::toString() const
     return QString::fromUtf8(stringFromId.value(m_id).str);
 }
 
+/*! \internal */
+Key Id::toKey() const
+{
+#ifdef QTC_USE_STORE
+    return name();
+#else
+    return toString();
+#endif
+}
+
 /*!
   Creates an id from a string representation.