Support composition for mobile keyboards

[gunsha]

Relevant components:

• Signalling server
• Frontend library
• Frontend UI library
• Matchmaker
• Platform scripts
• SFU

Problem statement:

Currently when using mobile keyboards using the suggestion bar or asian keyboards (chinese/japanese) is not supported as this uses the composition event on the keyboard

Solution

added composition event handler on mobile devices

Test Plan and Compatibility

working example of the changes implemented
https://arcanemirage.com/project/394?token=hLVbruBPrnR8

posible fix for #194

[github-actions]

PRs go stale after 30 days of inactivity. Please comment or re-open the PR if you are still working on this PR.

[lukehb]

Since this PR has been opened this commit was landed: 8b838f4

Is there other changes in this PR beyond support for composition events that we should consider? If so, please update the PR to the latest changes and update the description with any other issues it is addressing. However, I believe we support composition on mobile with the above linked commit?

[lukehb]

Bump @gunsha for you comments on the above. ^

[gunsha]

@lukehb can't find time to do a real test with the repo, but looking at the changes it's kind of the same I implemented, the only difference I see is that the composition and keypress events are always registered, i saw some input duplication when having both at the same time, so i'm only initializing composition on mobile and keypress on desktop

[lukehb]

@gunsha Let us know if you do see any duplication using what is in master currently. I am going to close for now as it is likely a new PR would be required if there is any bugfix for duplicated input.