Unit tests: Add a parsec_provider_init test with pre-generated parsec keys

[tgonzalezorlandoarm]

Use parsec-tool to generate a key out of bands

Add a parsec_provider_init test

The test checks if pre-generated keys can be accessed through the parsec client after initializing the provider.

This guarantees that:

 1) The parsec_provider_init function correctly initializes the
    parsec client.
 2) The parsec_provider_init function returns the correct pointer
    with the provider context.
 3) The parsec client is reachable through the provider context
    and is able to contact the parsec service.
 4) The pre-generated keys have been correctly stored through the
    parsec-tool

[tgonzalezorlandoarm]

Please check https://github.com/parallaxsecond/parsec-openssl-provider/actions/runs/8540977558

for the CI run with the newly built docker image

[tgonzalezorlandoarm]

https://github.com/parallaxsecond/parsec-openssl-provider/actions/runs/8541933970

[tgonzalezorlandoarm]

https://github.com/parallaxsecond/parsec-openssl-provider/actions/runs/8552530259