Feat/crypto jwe api

[HatemMn]

JOSE stands for JSON Object Signing and Encryption.
It groups together 4 core RFCs:

1. JWS (RFC 7515) : signing
2. JWE (RFC 7516) : encryption
3. JWK (RFC 7517) : key representation
4. JWA (RFC 7518) : algorithm identifiers

Another document will be followed: RFC 7519 - which sits on top of JOSE - it uses the JOSE Header and JOSE cryptographic operations, but adds the concept of claims.

In depth details are cited in the related issue : https://github.com/Cosmian/kms/issues/

How this was implemented :

First layer : crate/server/src/start_kms_server.rs

let crypto_scope = web::scope("/v1/crypto")
    .wrap(EnsureAuth::new(...))   // same auth middleware as KMIP
    .service(encrypt_handler)
    .service(decrypt_handler)
    .service(sign_handler)
    .service(verify_handler)
    .service(mac_handler);
app = app.service(crypto_scope);

The new API was registred the same way as other APIs such as CSE, DKE, etc.

Second layer : Hanlers, routes/crypto/*.rs

Each of these handlers :
Each handler does three things, nothing more:

1. Parses the JOSE request: decode base64url fields, extract alg/enc/kid from the protected header or request body
2. Convert JOSE identifiers to a KMIP operation struct
3. Forwards the call the its KMIP counterpart

Third layer : translation

This is the only new logic.
The KMS doesn't know what "ES256" is, or what a JOSE alg is. The file crate/server/src/routes/crypto/algorithm.rs translates the JOSE specs to a KMIP struct

Final layers : KMS Core

Nothing fundamental changes withing the KMS or crypto ops. Most the other diffs are wiring and plumbing and error handling (according to the request in the issue)

Closes #868