Introduce a general zkTLS plugin

[nkaskov]

To provide the AI Agents with a truly trustless zkTLS service, we need to have a corresponding plugin. Thankfully, some work has already been done in this PR. We can reuse the results and update the zkTLS plugin so it can work with arbitrary zkTLS providers. We also can add more verification options - at least for off-chain verification.

Depends on:

• Implementing the first public version of the interface library.
• Publishing an npmjs package of the zkTLS interface library