[vim] Generalized two-letter ESC sequences for insert mode

You can now edit vim.js and set enableEscKeymap to true and tweak
any related settings that you see fit and have a two-character
sequence to ESC from insert mode.
[vim] Add vim options for insert mode esc keys and cleanup
[vim] Fix macro recording for insert mode keys esc
[vim] Default insert mode esc keys back to false
[vim] Lint run
[vim] Move slightly misplaced comment.
Fix problem where a change to the selection causes unwanted history event merging

Issue #2717
[vim] undo changes separately after replaying actions and operators