Add default keyboard shortcuts to various actions in the FileSystem dock

Some of these shortcuts are inspired by Visual Studio Code's defaults.

- Ctrl + Alt + C: Copy Absolute Path
- Ctrl + Alt + Shift + C: Copy UID
- Ctrl + Alt + R: Open in File Manager
- Ctrl + Alt + E: Open in External Program
- Ctrl + Alt + T: Open in Terminal
  - Note: On Linux distributions that have Ctrl + Alt + T as a default
    shortcut to open a terminal, the system shortcut takes priority
    over this one.

The "Open Containing Folder in Terminal" text was shortened so that
the context menu doesn't become too wide with the default shortcut
annotations.

editor/filesystem_dock.cpp

@@ -3285,7 +3285,7 @@ void FileSystemDock::_file_and_folders_fill_popup(PopupMenu *p_popup, const Vect
 		const bool is_directory = fpath.ends_with("/");
 
 		p_popup->add_icon_shortcut(get_editor_theme_icon(SNAME("Terminal")), ED_GET_SHORTCUT("filesystem_dock/open_in_terminal"), FILE_OPEN_IN_TERMINAL);
-		p_popup->set_item_text(p_popup->get_item_index(FILE_OPEN_IN_TERMINAL), is_directory ? TTR("Open in Terminal") : TTR("Open Containing Folder in Terminal"));
+		p_popup->set_item_text(p_popup->get_item_index(FILE_OPEN_IN_TERMINAL), is_directory ? TTR("Open in Terminal") : TTR("Open Folder in Terminal"));
 
 		if (!is_directory) {
 			p_popup->add_icon_shortcut(get_editor_theme_icon(SNAME("ExternalLink")), ED_GET_SHORTCUT("filesystem_dock/open_in_external_program"), FILE_OPEN_EXTERNAL);
@@ -3891,17 +3891,17 @@ FileSystemDock::FileSystemDock() {
 
 	// `KeyModifierMask::CMD_OR_CTRL | Key::C` conflicts with other editor shortcuts.
 	ED_SHORTCUT("filesystem_dock/copy_path", TTR("Copy Path"), KeyModifierMask::CMD_OR_CTRL | KeyModifierMask::SHIFT | Key::C);
-	ED_SHORTCUT("filesystem_dock/copy_absolute_path", TTR("Copy Absolute Path"));
-	ED_SHORTCUT("filesystem_dock/copy_uid", TTR("Copy UID"));
+	ED_SHORTCUT("filesystem_dock/copy_absolute_path", TTR("Copy Absolute Path"), KeyModifierMask::CMD_OR_CTRL | KeyModifierMask::ALT | Key::C);
+	ED_SHORTCUT("filesystem_dock/copy_uid", TTR("Copy UID"), KeyModifierMask::CMD_OR_CTRL | KeyModifierMask::ALT | KeyModifierMask::SHIFT | Key::C);
 	ED_SHORTCUT("filesystem_dock/duplicate", TTR("Duplicate..."), KeyModifierMask::CMD_OR_CTRL | Key::D);
 	ED_SHORTCUT("filesystem_dock/delete", TTR("Delete"), Key::KEY_DELETE);
 	ED_SHORTCUT("filesystem_dock/rename", TTR("Rename..."), Key::F2);
 	ED_SHORTCUT_OVERRIDE("filesystem_dock/rename", "macos", Key::ENTER);
 #if !defined(ANDROID_ENABLED) && !defined(WEB_ENABLED)
 	// Opening the system file manager or opening in an external program is not supported on the Android and web editors.
-	ED_SHORTCUT("filesystem_dock/show_in_explorer", TTR("Open in File Manager"));
-	ED_SHORTCUT("filesystem_dock/open_in_external_program", TTR("Open in External Program"));
-	ED_SHORTCUT("filesystem_dock/open_in_terminal", TTR("Open in Terminal"));
+	ED_SHORTCUT("filesystem_dock/show_in_explorer", TTR("Open in File Manager"), KeyModifierMask::CMD_OR_CTRL | KeyModifierMask::ALT | Key::R);
+	ED_SHORTCUT("filesystem_dock/open_in_external_program", TTR("Open in External Program"), KeyModifierMask::CMD_OR_CTRL | KeyModifierMask::ALT | Key::E);
+	ED_SHORTCUT("filesystem_dock/open_in_terminal", TTR("Open in Terminal"), KeyModifierMask::CMD_OR_CTRL | KeyModifierMask::ALT | Key::T);
 #endif
 
 	// Properly translating color names would require a separate HashMap, so for simplicity they are provided as comments.