boxes: Display edit_text on newline.

This commits displays `edit_text` on a newline to differentiate
clearly what is searched for, add aesthetic appeal by using `\n > `
and better render long `edit_text`s.

Tests updated.

Author: Rohitth007

tests/ui_tools/test_boxes.py

@@ -1247,7 +1247,7 @@ def test_write_box_header_contents(
 
 
 class TestPanelSearchBox:
-    search_caption = " Search Results  "
+    search_caption = " Search Results \n > "
 
     @pytest.fixture
     def panel_search_box(self, mocker):

zulipterminal/ui_tools/boxes.py

@@ -1841,7 +1841,7 @@ def keypress(self, size: urwid_Size, key: str) -> Optional[str]:
             self.panel_view.keypress(size, "esc")
         elif is_command_key("ENTER", key) and not self.panel_view.empty_search:
             self.panel_view.view.controller.exit_editor_mode()
-            self.set_caption([("filter_results", " Search Results "), " "])
+            self.set_caption([("filter_results", " Search Results \n"), " > "])
             self.panel_view.set_focus("body")
             if hasattr(self.panel_view, "log"):
                 self.panel_view.body.set_focus(0)