Remove old credentials files from features dir

* The non-refactored credentials code has been returned to its
original location. Inventories and Jobs pull in Credentials
based on its original location in the file structure.
* Apply margin to individual inputs instead of panels to have
consistent spacing at more narrow resolutions.
* Add placeholder for a Lookup component which will be necessary
to let users select an org for the credential.

awx/ui/client/lib/components/panel/_index.less

@@ -15,7 +15,7 @@
 }
 
 .at-Panel-body {
-    margin: @at-space-6x 0 0 0;
+    margin: 0;
     padding: 0;
 }