[feature]: fission server client

[hugomrdias]

• Integrate Agent in the client
• POST | /api/v0/auth/email/verify | Trigger email verification
• POST | /api/v0/account | Create a full account
• GET | /api/v0/account | Get latest account information
• GET | /api/v0/account/member-number | Get the account's member number
• POST | /api/v0/account/:did/link | Login from another device via email code
• PATCH | /api/v0/account/username/:username | Change an account's username
• PATCH | /api/v0/account/handle/:handle | Change the handle that's associated with an account
• DELETE | /api/v0/account/handle | Disassociate an account's handle
• DELETE | /api/v0/account | Delete an account
• GET | /dns-query | Perform a DNS-over-HTTPS request