Prefix editor's uniqueId with plugin name

In this way we minimize the chance of
generating non-unique id.

Change-Id: Idd177c5a4b44b17a58c2a944ec77b9517e91964e
Reviewed-by: Eike Ziller <eike.ziller@qt.io>

src/plugins/subversion/subversionconstants.h

@@ -30,6 +30,8 @@
 namespace Subversion {
 namespace Constants {
 
+const char SUBVERSION_PLUGIN[] = "SubversionPlugin";
+
 const char NON_INTERACTIVE_OPTION[] = "--non-interactive";
 enum { debug = 0 };