The user timezone is only used for user's profile, so we can
move this setting to the Profile panel of settings and this
will also help us in covering some space when there are no
custom profile fields for the organization.
We separate "Your account" section to two different sections -
"Profile" section for user name, custom profile fields, and avatar
and "Account & Security" section for email, password, role, api-key
and deactivating button.
Another important change here is that the modal for changing name
is removed and now the name has a simple input text box and it
behaves similar to inputs for custom-profile-fields.
Fixes#18848.