fix(PocketIC): consensus registry version of instance resumed from existing state

[mraszyk]

This PR fixes the consensus registry version of a PocketIC instance resumed from an existing state: for canister http outcalls to work that registry version must be equal to the latest registry version which was not the case for a PocketIC instance resumed from an existing state (in that case the consensus registry version was equal to the registry version at which the corresponding subnet was created which is not always equal to the latest registry version if there are multiple subnets).

More details:

• the function check_share_against_context requires the registry version of the canister http outcall share (set to the latest registry version by PocketIC) to match the consensus registry version retrieved from the consensus pool cache set by PocketIC here when loading an existing subnet and here when creating a new subnet;
• the function make_registry_cup used so far creates a CUP with the registry version at which the corresponding registry key catch_up_package_contents_{subnet_id} was inserted into the registry (the registry version at which the corresponding subnet was created by PocketIC);
• the function make_registry_cup_from_cup_contents used in this PR creates a CUP with a registry version specified in the function's input parameters which allows PocketIC to use the latest registry version in the CUP.