Add support for forwarding touch keyboard input to the application

[valiantgamingpoint-prog]

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Related issue: #847

[Xananax]

Thank you for this PR. It does work well, I tested it on Firefox Android with the FUTO keyboard. I appreciate the attention to details and blocking arrows scrolling.

This said, I am hesitant to pull it into the main branch. The reason we didn't implement the keyboard this way is that it lacks support for tab.

We didn't decide on a solution for this. We considered:

1. Automatically convert double-space to tab, but it wouldn't be an obvious feature without some kind of warning and animation. It could also have false positives.
2. Automatically convert space at the beginning of a line to tabs. So matching against ^\s, and ^\t+\s. This too though is non-obvious and could defy expectations.
3. We looked at other applications, and realized almost all coding applications add their own bar on top of the keyboard, with special keys like tab, escape and so on. This is probably the cleanest solution, but requires quite a bit more work. I'm also not sure if can hide/show the bar only when the keyboard is shown/hidden. Finally, while most applications like Termux and co need to present multiple new keys such as escape, tab, tilda, and so on, we really only need tab, so the design might be a little awkward.
4. There might be other solutions, but these are the ones I remember we identified when we discussed this internally.

If this was an application for people who know how to code, then not having any of this would be ok. But since this is an application aimed at people who might have never coded before, leaving them without any obvious way to enter a tab character is problematic.

I'm not convinced by any of the solutions above, to be honest.

I'm open to any suggestion you may have (or anyone else reading).

Note: once we reach an agreement, I'll review your code, but I'd rather not tell you to change anything before we know if we want the code in. I looked at it quickly, it all seems good for me, but if we find a way to make it work, I'll ask you to port the JS code into bootstrap.js, following the structure there. I can help you with that when the time comes.

[NathanLovato]

I'll be keeping this around for reference but we wouldn't be able to merge this as it is.

The comments look off though that's just a matter of cleaning things up. Most importantly there's what Jad explained and more generally the user experience side of things that's needed to address issue #847. See the last comment in #847. If anyone reads this and would like to participate to this, that would be most welcome.