[DEV-6748] keeping history.replace() UX in place.

I tried to do history.push() so you could reload previous
hashes, but it's not as straight forward as I thought it would
be, so I'm removing it from the scope of this PR and into
[DEV-6783](https://federal-spending-transparency.atlassian.net/browse/DEV-6783)

src/js/containers/search/SearchContainer.jsx

@@ -205,7 +205,7 @@ const SearchContainer = ({ history }) => {
         request.current.promise
             .then((res) => {
                 // update the URL with the received hash
-                history.push({
+                history.replace({
                     pathname: `/search/`,
                     search: `?${new URLSearchParams({ hash: res.data.hash }).toString()}`
                 });

tests/containers/search/SearchContainer-test.jsx

@@ -99,8 +99,8 @@ test('a hashed url makes a request to the api & sets loading state', async () =>
 test('when filters change (a) hash is generated, (b) loading is set & (c) url is updated', async () => {
     restoreUrlHash.mockClear();
     const setLoading = jest.spyOn(appliedFilterActions, 'setAppliedFilterEmptiness');
-    const mockPush = jest.fn();
-    const { rerender } = render(<SearchContainer history={{ push: mockPush }} />, {});
+    const mockReplace = jest.fn();
+    const { rerender } = render(<SearchContainer history={{ replace: mockReplace }} />, {});
 
     jest.spyOn(redux, 'useSelector').mockReturnValue({
         ...mockRedux,
@@ -112,12 +112,12 @@ test('when filters change (a) hash is generated, (b) loading is set & (c) url is
         }
     });
 
-    rerender(<SearchContainer history={{ push: mockPush }} />, {});
+    rerender(<SearchContainer history={{ replace: mockReplace }} />, {});
 
     await waitFor(() => {
         expect(generateUrlHash).toHaveBeenCalledTimes(1);
-        expect(mockPush).toHaveBeenCalledTimes(1);
-        expect(mockPush).toHaveBeenLastCalledWith({
+        expect(mockReplace).toHaveBeenCalledTimes(1);
+        expect(mockReplace).toHaveBeenLastCalledWith({
             pathname: '/search/',
             // not ?hash=str because we aren't mocking out new URLSearchParams
             search: '?str'