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/admin/orgs.go

@@ -25,7 +25,8 @@ func Organizations(ctx *context.Context) {
 	ctx.Data["PageIsAdminOrganizations"] = true
 
 	explore.RenderUserSearch(ctx, &models.SearchUserOptions{
-		Type: models.UserTypeOrganization,
+		Actor: ctx.User,
+		Type:  models.UserTypeOrganization,
 		ListOptions: models.ListOptions{
 			PageSize: setting.UI.Admin.OrgPagingNum,
 		},