Adding a more realistic testing policy

[DAM-Philippon]

Currently, the testing policy is using three different parameters: the capacity in terms of test per hour, testing only symptomatic people, and allowing tests on the same Individual at different time steps.

While this is useful, it still remains over-simplistic. I've looked at the data in terms of testing (PCR) capacity for Vinh Phuc, and actually, there is none. This does not automatically means that no testing should be performed, but that samples are being sent to another province/clinic.

This "trip" should be represented, as it may induce a delay between the test being performed and the response (i.e. sending the Individual to quarantine, for instance), possibly letting one infectious Individual infecting others.

One possible way would be to keep in memory tests being perform for an Individual in a map, and "release" the answer after X steps (days) have passed. This delay would be added as an attribute of the new DelayedDetectionPolicy.