fix: make date range parameters optional in useStacSearch hook

- Changed dateRangeFrom and dateRangeTo from required to optional in return type
- Updated state initialization to use undefined instead of empty strings
- Updated setters to accept optional string parameters
- Updated reset function to set undefined instead of empty strings

This resolves type inconsistencies where the return type claimed required strings
but the implementation initialized with empty strings. Conceptually, users should
be able to clear/unset date filters by passing undefined.

Author: AliceR

src/hooks/useStacSearch.ts

@@ -23,10 +23,10 @@ type StacSearchHook = {
   setBbox: (bbox?: Bbox) => void;
   collections?: CollectionIdList;
   setCollections: (collections?: CollectionIdList) => void;
-  dateRangeFrom: string;
-  setDateRangeFrom: (date: string) => void;
-  dateRangeTo: string;
-  setDateRangeTo: (date: string) => void;
+  dateRangeFrom?: string;
+  setDateRangeFrom: (date?: string) => void;
+  dateRangeTo?: string;
+  setDateRangeTo: (date?: string) => void;
   sortby?: Sortby[];
   setSortby: (sortby?: Sortby[]) => void;
   limit: number;
@@ -48,8 +48,8 @@ function useStacSearch(): StacSearchHook {
   const [ids, setIds] = useState<string[]>();
   const [bbox, setBbox] = useState<Bbox>();
   const [collections, setCollections] = useState<CollectionIdList>();
-  const [dateRangeFrom, setDateRangeFrom] = useState<string>('');
-  const [dateRangeTo, setDateRangeTo] = useState<string>('');
+  const [dateRangeFrom, setDateRangeFrom] = useState<string>();
+  const [dateRangeTo, setDateRangeTo] = useState<string>();
   const [limit, setLimit] = useState<number>(25);
   const [sortby, setSortby] = useState<Sortby[]>();
 
@@ -63,8 +63,8 @@ function useStacSearch(): StacSearchHook {
     setBbox(undefined);
     setCollections(undefined);
     setIds(undefined);
-    setDateRangeFrom('');
-    setDateRangeTo('');
+    setDateRangeFrom(undefined);
+    setDateRangeTo(undefined);
     setSortby(undefined);
     setLimit(25);
     setCurrentRequest(null);