Move probe storage allocation to an externally defined and injected function

[phsmenon]

Context: MCTrace supports platform-specific allocation of the telemetry storage block. Currently the allocation is handled by a set of hardcoded instructions in the platform-specific plugin. Instead, the allocation function should be defined as part of an external (compiled) module. MCTrace must be updated to inject this module in to the binary and make calls these functions as appropriate.

To achieve this MCTrace must support injecting external modules in to the binary and invoking these newly injected functions afterwards.

Note that this approach can also be used to support externally specified data exfiltration functions.

See also #9.