SLING-5648 - Make Non-Eclipse Module regular Maven Packages

Make the impl-vlt bundle a singleton, otherwise Eclipse does not
parse the extension points.
diff --git a/shared/modules/impl-vlt/bnd.bnd b/shared/modules/impl-vlt/bnd.bnd
index ced3679..0aff61c 100644
--- a/shared/modules/impl-vlt/bnd.bnd
+++ b/shared/modules/impl-vlt/bnd.bnd
@@ -1,2 +1,3 @@
 -exportcontents: ${packages;VERSIONED}
--includeresource: plugin.xml, .options
\ No newline at end of file
+-includeresource: plugin.xml, .options
+Bundle-SymbolicName: org.apache.sling.ide.impl-vlt;singleton:=true