[#361] Improve search result page (#375)

* [#361] added back button

* [#361] greatly improved looks of results

* [#361] added popup on click

* [#361] removed classnames with \!important replaced with style in component

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Co-authored-by: Camille Moussu <cmoussu@linagora.com>

__test__/features/Search/SearchResultsPage.test.tsx

@@ -199,7 +199,6 @@ describe("SearchResultsPage", () => {
     });
 
     expect(screen.getByText("Untitled Event")).toBeInTheDocument();
-    expect(screen.getByText("-")).toBeInTheDocument();
   });
 
   it("should format all-day events correctly", () => {