Bugfix in sorterByMetadataField - reverse order working correctly now

- new unit tests

src/custom-sort/custom-sort.spec.ts

@@ -2254,6 +2254,25 @@ describe('CustomSortOrder.byMetadataFieldAlphabeticalReverse', () => {
 		expect(result1).toBe(SORT_FIRST_GOES_EARLIER)
 		expect(result2).toBe(SORT_FIRST_GOES_LATER)
 	})
+	it('should put the item with metadata later if the second one has no metadata (reverse order)', () => {
+		// given
+		const itemA: Partial<FolderItemForSorting> = {
+			metadataFieldValue: '15',
+			sortString: 'n123'
+		}
+		const itemB: Partial<FolderItemForSorting> = {
+			sortString: 'n123'
+		}
+		const sorter: SorterFn = Sorters[CustomSortOrder.byMetadataFieldAlphabeticalReverse]
+
+		// when
+		const result1: number = sorter(itemA as FolderItemForSorting, itemB as FolderItemForSorting)
+		const result2: number = sorter(itemB as FolderItemForSorting, itemA as FolderItemForSorting)
+
+		// then
+		expect(result1).toBe(SORT_FIRST_GOES_LATER)
+		expect(result2).toBe(SORT_FIRST_GOES_EARLIER)
+	})
 	it('should correctly fallback to alphabetical reverse if no metadata on both items', () => {
 		// given
 		const itemA: Partial<FolderItemForSorting> = {