NF: factorize browser.current_search

I was looking at search code and find out that's already slightly more clear/short even if NF

qt/aqt/browser/browser.py

@@ -281,7 +281,7 @@ class Browser(QMainWindow):
     # search triggered by user
     @ensure_editor_saved
     def onSearchActivated(self) -> None:
-        text = self.form.searchEdit.lineEdit().text()
+        text = self.current_search()
         try:
             normed = self.col.build_search_string(text)
         except Exception as err:
@@ -580,7 +580,7 @@ where id in %s"""
             ChangeModel(self, nids)
 
     def createFilteredDeck(self) -> None:
-        search = self.form.searchEdit.lineEdit().text()
+        search = self.current_search()
         if self.mw.col.schedVer() != 1 and KeyboardModifiersPressed().alt:
             aqt.dialogs.open("FilteredDeckConfigDialog", self.mw, search_2=search)
         else:

qt/aqt/browser/sidebar/tree.py

@@ -933,9 +933,7 @@ class SidebarTreeView(QTreeView):
 
     def _get_current_search(self) -> Optional[str]:
         try:
-            return self.col.build_search_string(
-                self.browser.form.searchEdit.lineEdit().text()
-            )
+            return self.col.build_search_string(self.browser.current_search())
         except Exception as e:
             showWarning(str(e))
             return None