Serviceability needs AccessPass account to store current access authorization by a user

[jeffgrunewald]

The Serviceability contract needs a temporary account type and instructions for creating/updating them to record on the DoubleZero ledger that a user has properly authenticated to the network such that the Activator is able to verify their eligibility for being issued a connection.

• The AccessPass (name tbd) can only be created by the sentinel authority as verification on the DZ ledger that a user account represent a qualifying validator subject to the revenue sharing agreement for post-paid access or a pre-paid user that has deposited the necessary 2z tokens for access
• The AccessPass account for pre-paid users indicates the epoch at which time the user's access expires.
• The AccessPass account indicates the account type in some way as pre-paid or post-paid. This could be an enum flag on the account or the initial implementation could simply be implied by the presence of the end-of-access epoch for pre-paid users from the previous point or the absence of a ttl for post-paid validators.
• The AccessPass account needs to record the IP address of the connecting user

[juan-malbeclabs]

@jeffgrunewald @karl-dz The Access Pass will be implemented without being used for access control in order to test the development, and later it will be integrated with user access control.