Add Visible modes function from Organisation to Users too (#16069)

You can limit or hide organisations. This pull make it also posible for users

- new strings to translte
- add checkbox to user profile form
- add checkbox to admin user.edit form
- filter explore page user search
- filter api admin and public user searches
- allow admins view "hidden" users
- add app option DEFAULT_USER_VISIBILITY
- rewrite many files to use Visibility field
- check for teams intersection
- fix context output
- right fake 404 if not visible

Co-authored-by: 6543 <6543@obermui.de>
Co-authored-by: Andrew Thornton <art27@cantab.net>

routers/web/user/setting/profile.go

@@ -114,6 +114,7 @@ func ProfilePost(ctx *context.Context) {
 	}
 	ctx.User.Description = form.Description
 	ctx.User.KeepActivityPrivate = form.KeepActivityPrivate
+	ctx.User.Visibility = form.Visibility
 	if err := models.UpdateUserSetting(ctx.User); err != nil {
 		if _, ok := err.(models.ErrEmailAlreadyUsed); ok {
 			ctx.Flash.Error(ctx.Tr("form.email_been_used"))