Allow user to disable closing multiple tabs

[benwaffle]

I'm opening this issue because:

• I'll report a bug
• I'll propose a new feature

Description

Sometime I will type <N>d, e.g. 100d. I'll intend to type it into a text field but if I accidentally type it when the text field has lost focus, vim vixen will interpret it as "delete 100 tabs". I'd like to disable this functionality, but ideally be able to keep the singular delete tab command.

Steps to Reproduce

Please provide detailed steps for reproducing the issue.

1. type 100d
2. lose all your tabs

System configuration

• Operating system: MacOS 12.2.1
• Firefox version: Firefox 100.0
• Vim-Vixen version: 1.2.3