enhance Vi KeyMap with most Vi movement commands

This includes support for `,` and `;`.

These move backwards to the end of a word, the reverse of `e` and `E`.

Inclusive delete operations include the end position in the operation.

This command will include the current cursor position in the delete
operation instead of excluding that character.

add KeyMap for vi

These commands delete and change (delete then insert mode) the text
covered by the next movement command.

This command replaces count characters with the given character.

The `s` command deletes count chars and enters insert mode.

This function deletes all the characters between the cursor and the
given position.

This also properly marks the start and end of undo groups in order to
properly support undoing and redoing commands with counts and insert
commands.

This is necessary to support proper undoing in insert mode.

This command repeats the last normal command or the last insert
command. It also supports counts.

This will repeat the last insert `count` times.

This will be used later. Right now we just properly track the count.

This includes support for basic vi movements and insert and normal mode.

This release includes support for detecting Esc key presses.

This is necessary for vi normal mode.

This code should be shared across all key mappings.

It is now unused.

Right now this is just a simple passthrough to Editor, but this will
change.