Bug 27680: Add tests for various ways of passing multi-params

Bug 27680: Add tests for various ways of passing multi-params

This patch adds unit test to increase the coverage of parameter that
accept multiple values.  There are a number of different ways end users
can send such parameters and we should test to ensure we are recieving
the correct option.

Options
`?param1=this&param1=that` - traditional multiple pass params
`?param1[]=this&param1[]=that` - php multiple pass params
`?param1=this,that` - comma delimited list param
`?param1=this|that` - pipe delimited list param

Signed-off-by: Tomas Cohen Arazi <tomascohen@theke.io>
Signed-off-by: Jonathan Druart <jonathan.druart@bugs.koha-community.org>
Signed-off-by: Jonathan Druart <jonathan.druart@bugs.koha-community.org>