Allow optional forced deletion of zootopia conflict

[RocketMan]

Current ZootopiaListener behaviour is to end pre-maturely any show when a conflict is detected, such as a DJ's starting an ad-hoc show. ZootopiaListener deletes the show instead of ending it only if the show would have length less than the minimum, typically 15 minutes.

This issue proposes to add an optional configuration parameter to the ZootopiaListener configuration that would force deletion in all cases.

Proposed behaviour: If the parameter is present and true, a conflicting show would be deleted in all cases; if false or omitted, then legacy semantics would apply.

[RocketMan]

patch landed and deployed to prod; closing