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

Allow sending text after `shrug`

¯\_(ツ)_/¯ IDK, I like to write something after, sometimes

Allow sending:

¯\_(ツ)_/¯ some text

By entering:

/shrug some text

It's supported in Element. If you did it in nheko, you just used to lose the
extra text.

Not putting text is still supported, a ternary operator makes sure a
space is only inserted if the text isn't empty, to avoid having a trailing
space.

Improve wording in multiple strings.

This is for consistency with "Start a private chat", and is more
specific.

This is less ambiguous. Moreover, this mode might be useful on a
computer touchscreen.

This is less ambiguous, as it aligns with the other uses.

Trusted might refer to something else, like the reputation project.
You can trust a user you haven't verified.

Also mention devices as this shares keys with verified devices, for when device
verification was performed without cross-signing.

Replace it with "verification process".

Fix crash when stun server selected

Support video calls

Optimize build

Currently translated at 31.3% (129 of 411 strings)

Co-authored-by: Priit Jõerüüt <nhkwlate@joeruut.com>
Translate-URL: https://weblate.nheko.im/projects/nheko/nheko-master/ru/
Translation: Nheko/nheko

Currently translated at 50.1% (206 of 411 strings)

Co-authored-by: Priit Jõerüüt <nhkwlate@joeruut.com>
Translate-URL: https://weblate.nheko.im/projects/nheko/nheko-master/fi/
Translation: Nheko/nheko

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

Currently translated at 100.0% (411 of 411 strings)

Co-authored-by: Priit Jõerüüt <nhkwlate@joeruut.com>
Translate-URL: https://weblate.nheko.im/projects/nheko/nheko-master/et/
Translation: Nheko/nheko

Currently translated at 100.0% (411 of 411 strings)

Co-authored-by: Joseph Donofry <rubberduckie3554@gmail.com>
Translate-URL: https://weblate.nheko.im/projects/nheko/nheko-master/en/
Translation: Nheko/nheko