Only clear filter query when closing search panel

As part of the filter UI overhaul we want to make it easier to toggle filters
independently, which enables going back / forward one step at a time. For the
search panel, this means that closing search should not affect other filters.

src/sidebar/components/search/SearchPanel.tsx

@@ -19,7 +19,7 @@ export default function SearchPanel() {
       initialFocus={inputRef}
       onActiveChanged={active => {
         if (!active) {
-          store.clearSelection();
+          store.setFilterQuery(null);
         }
       }}
     >

src/sidebar/components/search/test/SearchPanel-test.js

@@ -8,7 +8,6 @@ describe('SearchPanel', () => {
 
   beforeEach(() => {
     fakeStore = {
-      clearSelection: sinon.stub(),
       setFilterQuery: sinon.stub(),
       filterQuery: sinon.stub().returns(null),
       closeSidebarPanel: sinon.stub(),
@@ -36,7 +35,11 @@ describe('SearchPanel', () => {
 
       wrapper.find('SidebarPanel').props().onActiveChanged(active);
 
-      assert.equal(fakeStore.clearSelection.called, !active);
+      if (!active) {
+        assert.calledWith(fakeStore.setFilterQuery, null);
+      } else {
+        assert.notCalled(fakeStore.setFilterQuery);
+      }
     });
   });