[NEW] Add "real name change" setting

[AmShaegar13]

@RocketChat/core

Closes #8576

Added a setting to allow real name updates. This was necessary after avatar updating was merged into profile page. One could not allow avatar updates while forbidding name changes (implicitly with fobidding profile updates at all). I used the exact same logic as the username setting does.

Just one question: How about the languages I do not speak? Do I just omit them or fill i18n JSONs with placeholders?

[cyclops24]

@AmShaegar13 Thanks for this PR. Usually guys fill English and omit other languages for translators.

[AmShaegar13]

I added some tests to ensure it's working as intended. Should be ready to merge after checks are green.

[gdelavald]

Thanks for your PR, we'll review it and provide feedback when possible.

[AmShaegar13]

My new tests are failing. I am still searching for a clever way to make them pass reliably.

[AmShaegar13]

Okay, tests are green. I am done. :)

[ggazzo]

@AmShaegar13 approved ;)

[dajoker]

I see this is still open; has it been merged at all, or could it be? If working, it s something our users would like. In our case we have disabled Profile changes, but would like Avatar changes still, so that may not be part of what was originally scoped here.

[AmShaegar13]

@dajoker This PR was merged and is not open anymore. You can use it from Administration -> Account -> Allow Name Change