composeBox: Limit maxHeight to 110.

[jainkuniya]

Most chat apps limit the height of composeBox, and then text box
becomes scrollable on further entering text. FB messenger and WhatsApp
limit to 6 lines of text. Following the same pattern, limit the max
height of message input.

Fixes: #3048

[borisyankov]

I am a bit suspicious that 110 equal 6 lines (would be true only if the line-height is 18.3333333 😄 )

Regardless, we used to have this exact limit, but as I vaguely recall @timabbott wanted to be able to enter more text in the mobile app compared with other mobile apps (consistently with a tendency to write longer text on the web app).

I don't think the 'unlimited height' behavior is ideal, but neither is limiting it to 6-ish lines. Extra points for tracking the commit that did the change or the issue that it resolved to remind us of what was the reason to remove the limit,

[armaanahluwalia]

I agree with @borisyankov. I don't think setting a max height really solves anything and takes away the ability to effectively use the ComposeBox as a space for drafting long messages. I've also made a small tweak to this code in #2887

I just filed #3052 #3053 in case you're in the mood for text input stuff which to me are bigger problems while composing.

[timabbott]

I've definitely composed messages longer than 6 lines of text in the current Zulip app (and I think copying Messenger and WhatsApp isn't right for our context, because Zulip, being a work tool, is generally going to have more reason to send long messages explaining complex ideas). I do think we need to have a reasonably scrolling situation for this, but I think limiting to 6 lines is counterproductive.

[borisyankov]

Then we want to grow the compose box up to the height of the whole screen when the keyboard is popped up. (height = screen.height - keyboard.height).
If the user wants to see what was written, they can hide the keyboard.
I'll do the change, as there are few more changes around this that I am working on.