Add v1.generate({seed}) feature, to match did:key driver

[dmitrizagidulin]

Add the ability to generate a new Veres One DID from a seed, to match did:key driver.
(Just like with did:key, if a seed param is present, use it to generate a capabilityInvocation key.)

Note: Make the PR off of #60 / v14.x branch.

[msporny]

Where do we use this feature? Why do we need it?

[dmitrizagidulin]

@msporny - we use this in did-io, and were using it in our admin CLI tool.

[msporny]

@msporny - we use this in did-io, and were using it in our admin CLI tool.

Yes, but why? What's the use case? Someone wants to use an external random number generator for a seed? Someone wants to physically imprint the seed on titanium plates?

[aljones15]

just a small note, this makes did-veres-one have the same generate interface as did-method-key. This helps as right now if you want your app to be cross-compatible with did-method-key and did-veres-one you have to generate did-method-key from a 32-byte Uint8Array and then did-veres-one from an Ed25519Key. Basically, did-veres-one requires an extra step.

[aljones15]

I believe this can be closed as this was is now a feature in v14.x #75

[JSAssassin]

Closing, implemented.