Input: Support chorded key-presses

[bryphe]

Today our InputManager does not handle chorded key presses, like inputManager.bind("jk", () => { ... }).

It'd be great to be able to handle this, as it would be one less case where a user has to 'eject' from Oni's input configuration to go to their init.vim.

Some considerations:

• We'd need a setting for how long to 'wait' for the binding to complete
• We'd need to decide how to handle the case where both j and jk are bound - AFAIK, Vim actually waits for the time with a single press, unless it is cleared by another key press that is unmapped.

[ShaneDelmore]

Isn’t chorded jk and jj repeated?

[bryphe]

Sorry, bad example on my part - updated to reflect jk instead to make it clearer.

[CrossR]

Can this be closed @bryphe?