Adding Data, DataObject, FileDrop and Text tests to ClipboardCoreTests#13645

LeafShi1 wants to merge 4 commits intodotnet:maindotnet/winforms:mainfrom

LeafShi1:Move_ClipboardTest_To_ClipboardCoreTestsLeafShi1/winforms:Move_ClipboardTest_To_ClipboardCoreTestsCopy head branch name to clipboard