Add protocol version information to fields on `NetworkParameters`

[arya2]

Motivation

We want to make these values configurable on Testnets:

• INITIAL_MIN_NETWORK_PROTOCOL_VERSION
• CURRENT_NETWORK_PROTOCOL_VERSION
• min_specified_for_upgrade

See https://github.com/ZcashFoundation/zebra/pull/7924#discussion_r1385877140.

Outdated:

These have already been added.

• FUNDING_STREAM_HEIGHT_RANGES
• FUNDING_STREAM_ADDRESSES

Possible Design

Check what values zcashd uses for Regtest and either:

• Add them to these HashMaps for Testnet with Regtest parameters (this support custom testnets, only Regtest), or
• Add them as fields in NetworkParameters and set the Regtest values in Network::new_regtest (#7839):

[arya2]

This isn't a priority right now

[arya2]

We still want to move INITIAL_MIN_NETWORK_PROTOCOL_VERSION to a field on testnet::Parameters.

[arya2]

This is mostly cleanup, but if we make this change and also allow for defining consensus branch ids in the config, we could participate in the following round of private Testnet testing without making any code changes.

[mpguerra]

not a priority right now