Add some missing keyboard hints to file dialogs

src/rogallo/screens/main/screen.py

@@ -615,6 +615,7 @@ async def download_uri(self, message: DownloadURI) -> None:
                     title=f"Download {location}",
                     default_file=Path(location.path).name,
                     save_button="Download",
+                    cancel_button=partial(add_key, key="Esc", context=self),
                 )
             )
         ):

src/rogallo/widgets/side_panel/client_certificates.py

@@ -2,6 +2,7 @@
 
 ##############################################################################
 # Python imports.
+from functools import partial
 from itertools import chain
 from typing import Final
 
@@ -16,6 +17,7 @@
 # Textual enhanced imports.
 from textual_enhanced.binding import HelpfulBinding
 from textual_enhanced.dialogs import Confirm, ModalInput
+from textual_enhanced.tools import add_key
 from textual_enhanced.widgets import EnhancedOptionList
 
 ##############################################################################
@@ -403,6 +405,7 @@ async def action_export(self) -> None:
                         else "certificate.pem",
                         filters=_FILE_FILTERS,
                         save_button="Export",
+                        cancel_button=partial(add_key, key="Esc", context=self),
                     )
                 )
             )
@@ -428,6 +431,7 @@ async def action_import(self) -> None:
                 filters=_FILE_FILTERS,
                 open_button="Import",
                 title="Import Certificate",
+                cancel_button=partial(add_key, key="Esc", context=self),
             )
         ):
             try: