OPTEE Remote Attestation based on Veraison Verifier

[kunisuzaki]

We have moved from OP-TEE Remote Attestation, which was merged at OP-TEE/optee_os#7006.
We now plan to add an example to optee_examples.

The original example is available at https://github.com/iisec-suzaki/optee-ra, but we are customizing it to run on a single machine.
To achieve this, we will use Docker to run the Veraison Verifier.
Please let us know if you have any ideas or comments.