mutation_test: Add allocation failure stress test for apply()
mutation_test: Add allocation failure stress test for apply()

The test injects allocation failures at every allocation site during
apply(). Only allocations throug allocation_strategy are instrumented,
but currently those should include all allocations in the apply() path.

The target and source mutations are randomized.

duarten/scylla,raphaelsc/scylla,kjniemi/scylla,avikivity/scylla,duarten/scylla,avikivity/scylla,raphaelsc/scylla,scylladb/scylla,raphaelsc/scylla,scylladb/scylla,scylladb/scylla,scylladb/scylla,duarten/scylla,kjniemi/scylla,avikivity/scylla,kjniemi/scylla