Enable development and testing on non-SGX and non-Intel hardware

[mcamou]

SGX emulation does not work in some platforms, for example M-series Macs or some Intel CPUs (specifically tried with an Intel Core Ultra 9 185H). Even in simulation mode, eGo crashes.

We should be able to separate out the cryptographic primitives used and use some standard library perhaps with a fixed key. That would enable us to run without ego, therefore allowing us to streamline development on hardware where the eGo simulator is not supported.

Acceptance criteria

• You can enable a testing mode via an environment variable, that does not run using eGo
• There is an easy, documented way of running in this way
• Tested on M-series Macs and Intel Core Ultra 185H (and other platforms that we find along the way where the eGo simulator does not run).