The strings for these files were taking up a lot of space, making browsing memfs.ts difficult

Closes #97823

* Fixes #97012

* minor renames
Co-authored-by: NSteVen Batten <stbatt@microsoft.com>

Change "Cursor Move Down" commands to more generic "focus next editor" commands, add keybinding to move down out of output, and add context key for "output is focused"

Have to fix again after changing how cell list focus works

Moved common registration properties to NotebookAction,
force registering in CommandPalette

Fixes #99906

fixes #82759

fixes #99564

Fix #99253

#93368 Replace biased util with using extUri based on fileservice provider's case sensiive capability