Mitigate webrtc race condition

fix #292

move error_matrixid label below matrixid input, made hide/show for the label, made red underline for invalid input, add to TextField class isValid() setValid() for custom validation

Added QLabel for matrixIdError output and added new function which output input id error, improve code like suggest @deepbluev7, return for error_label setWordWrap

Russian translate

Co-authored-by: Emilie <em@nao.sh>

Make compatible with qt 5.12

Make incoming call ringtone a user setting

Smooth all the things [v2]

Video calls: add local webcam view

Update README with element.io

Currently translated at 100.0% (411 of 411 strings)

Co-authored-by: Mayeul Cantan <mayeul.cantan@gmail.com>
Translate-URL: https://weblate.nheko.im/projects/nheko/nheko-master/fr/
Translation: Nheko/nheko

There is no need to iterate over a list, flags can be applied and stored
simultaneously.

This helps on low-dpi screens, getting rid of the jaggies.

Allow sending text after `shrug`