Refactory and Working Tests

[davxy]

• use SW instead of ED form (to match ring-proof requirements)
• actively use ring-proof
• a couple of tests
• expose RingVrfSignature and VrfSignature components to allow usage in substrate (we are using Vec of VrfPreOut)
• insecure_kzg_setup takes a generic Rng parameter.
• Introduced testing_kzg_setup to be used within tests

[burdges]

Apologies for the delay.