Support repeatable key bindings

[spywhere]

Commands such as resize the pane are expected to be repeatable, that is to be able to hold the key sequence to repeat the operation. Currently this would get consumed by vim as the sequence is required 2 steps (prefix then the key).

Idea for implementation

Create a custom key map table. Pressing prefix would rebind all vim key map to all key bindings starts with prefix. Then if there is no key press after certain amount of time, cancelled the key map back to the previous one.

This would mimicking a custom mode in vim, where pressing prefix could put vim into "tmux" mode.

Current workaround

Use vim count to repeat the key bindings for certain amount of times.