We should respect the users choice. We can still get their email from the user id if we really need to.

preparing for #5664 with some test improvements i ran into this issue

This commit includes a fix and the test improvements. In particular it
adds BrowserIntegrationTest#login - so there is no need to go through the signup procedure everytime you want a user to be logged in.

the loading... text on the buttons was not capitalized before.

So in order to change this in a (more or less) single place i added
new button types to simple_form:

button :wrapped - normal button, with loading and an optional cancel button wrapped in the classical bootstrap action div.
    cancel option contains the url to go to when canceling.

button :loading - simple button with loading text capitalized by using i18n (simple_form.buttons.loading)

Conflicts:
	engines/support/app/views/tickets/new.html.haml

Feature/api quota support + current_user null pattern

Bugfix/5549 prefer client signup

cost  -> rate
quota -> storage

The changes to the configuration required some non minor changes to the platform and also added some flexibility we don't require yet - and thus some new possibilities for errors.

So instead we still use the allow_..._certs and ..._cert_prefix options.
They basically provide the framework in which service levels can operate.

The service level configuration will not include the cert prefix anymore.
It only states if the service level is rate limited or not.
This avoids conflicts between the two configuration options.

I also removed the anonymous service level entirely.
It was also turning a boolean decision (do we provide anonymous eip or not) into something way more complex. Instead I added the AnonymousServiceLevel class to handle the corner cases for people who are not logged in.

Furthermore i renamed the UnauthenticatedUser to AnonymousUser so it matches the Anonymous Service Level nicely. It's also shorter and more intuitive.