compoundFilter: one tag is a string, not an array - convert to array

fixes being unable to add more tags to filter when filtering by 1 tag
(it works when 0 tags, falling back to []; works when 2+ tags because it is automatically an array; but fails to add/remove tags when only one is selected)

Author: himdel

src/components/patternfly-wrappers/compound-filter.tsx

@@ -242,9 +242,17 @@ export class CompoundFilter extends React.Component<IProps, IState> {
 
   private onSelectMultiple = (event) => {
     let newParams = this.props.params[this.state.selectedFilter.id];
+
+    // no tags => falsy
+    // 1 tag => "foo"
+    // 2+ tags => ["foo", "bar"]
+    // convert all to an array
     if (!newParams) {
       newParams = [];
     }
+    if (!Array.isArray(newParams)) {
+      newParams = [newParams];
+    }
 
     // TODO: Remove this replace after patternfly fixes the pf-random-id issue
     const selectedID = event.currentTarget.id.replace(/pf-random-id-\d+-/, '');
@@ -256,6 +264,7 @@ export class CompoundFilter extends React.Component<IProps, IState> {
     } else {
       newParams.push(selectedID);
     }
+
     this.submitMultiple(newParams);
   };