Extend test for cancellations

[eynimeni]

We need to cover the cancel all booked users functions better with tests to see if the quota and the cancellation fee is correctly applied here.
Quota is defined in Cancellation Settings, there are two options: calculateconsumationfixedpercentage or calculateconsumation. The second one needs a callback function in the plugin of the item (i.e. mod_booking) returning a float value to for the price to be multiplied with (i.e 0.2 if 20% of the option in consumed).

given some users have booked a bookingoption

• Modal displaying list of booked users with correct price paid

• if we support tests for pricegroups, this would be great to test here as well - so different prices should be displayed according to the pricegroup of users and settings of bookingoption

• if quota is given in settings, display correct quota in modal

• Cancelation fee should be applied and overwrite standard cancellation fee (except for cancelling user himself - in this case, the standard fee should always apply)

• users should recieve credits: quota is deduced from given price in percentage, then cancellation fee is substracted

• In the first step, we need tests for calculateconsumationfixedpercentage applied

• eventually, we will extend them for calculateconsumationfixedpercentage 0 and calculateconsumation checkbox checked in settings

• the third parameter in cancellation options is the serviceperiod - as I am unaware of the status quo of tests in this regard, we treat this later