Implement deactivate_did RPC

[Vishwas1]

• https://www.tyronzil.com/CRUD-operations/did-deactivate/

[Vishwas1]

From w3c spec

If a DID has been deactivated, DID document metadata MUST include this property with the boolean value true. If a DID has not been deactivated, this property is OPTIONAL, but if included, MUST have the boolean value false.

The DID method specification MUST specify how a DID controller can deactivate a DID or state that deactivation is not possible.

Add new did_deactivate RPC

Input: similar to update DID

1. Query the lastest version of did
2. Check if the did is already deactivated, otherwise throw did_deactivation_err
3. Check if contoller is trying to deactivate or not, otherwise throw authorization_err.
4. Verify the signature, otherwise throw invalid_siganture_err
5. Set DID metadata:didDoc.metadata.deactivate == true & didDoc.did == null / {}

Update the did_resolve query RPC

• Add check if the did is already deactivated, if so then send error did_resolve_err, otherwise proceed.

Update the did_update rpc

• Add check if the did is already deactivated, if so then send error did_resolve_err, otherwise proceed.

[arnabghose997]

Discussion of treating deactivated DIDs : w3c/did-resolution#5