(feat) Cheqd DID resolver #1300

[gmulhearn]

Closes #1300

Implements a did:cheqd resolver using cheqd's gRPC resolver provided by nodes.

For this approach i decided to check-in cheqd's .proto type files, and also check in the generated rust files for these proto types. These rust files are generated using tonic, a defacto rust lib for handling grpc. I justify the decision to check-in the files in the README, please see there.

Testing

• there are some system & unit tests. system tests are using universal-resolver sample DIDs
• have tested consumption in anonyome's internal stack.
• have tested that internal stack against credo-ts testnet cheqd DIDs (including testing on android device).

Out of Scope (for now)

• doc version resolution
• DID resource resolution (including did-doc metadata with the resources metadata)

Other changes

• added some const context definitions in the did_doc crate, and a utility method to get the required context for a given VM type.
  • longer term, we may consider have some general "normalize" function of DIDDocuments, which scans the doc contents, finds all appropriate JSON-LD contexts, and adds them if they were missing.
• removed RsaVerificationKey2018 - unused legacy VM type
• added specific parsing for did:cheqd DIDs
• updates the did:web resolver to use hyper 1+. mostly following: https://hyper.rs/guides/1/upgrading/ . This was necessary, as hyper 0.14 & hyper-tls 0.5 had several issues with TLS on devices (e.g. android devices). Upgrading has fixed those issues (did:web can now resolve on android devices).