feat: store lightnode activations

[maharifu]

Related Github tickets

• Closes As a user, I want Paloma to track all light node activations on the Paloma blockchain so that the activation will allow application developers to authenticate LightNodes for new features. VolumeFi/paloma#2250
• Closes As a user, I want Paloma to add a transaction type in the Paloma protocol that only lightnodes can execute so that Paloma LightNodes can execute new features in the LightNode software VolumeFi/paloma#2251
• Closes As a user, I want the Paloma protocol to add a new Paloma governance vote to add all paloma lightnododes activated until now to the activation tracking ledger on the paloma protocol VolumeFi/paloma#2252

Background

Keep an on-chain list of activated lightnodes. When a new node is activated, we add it to the list. To bootstrap the list with the existing lightnodes, we add a new transaction. This is instead of a governance vote, so we don't waste more time. The transaction can be executed at any time after the upgrade.
For each lightnode we keep track of: address, activated timestamp, last authentication timestamp. This way we can also know which nodes are active and performing authentications.

Testing completed

• test coverage exists or has been added/updated
• tested in a private testnet

Breaking changes

• I have checked my code for breaking changes
• If there are breaking changes, there is a supporting migration.

[taariq]

Looks good and what we need! LFG!