feat(network): add new network config builder

[drichar]

Description

This PR introduces the NetworkConfigBuilder to enable customizable network configurations and support for custom networks. It provides a more flexible way to configure network settings, including CAIP-2 chain IDs, and allows applications to define their own networks beyond the default options:

1. mainnet
2. testnet
3. betanet
4. fnet
5. localnet

Examples

Using default network configurations

const manager = new WalletManager({
  wallets: [WalletId.DEFLY, WalletId.KIBISIS],
  defaultNetwork: NetworkId.MAINNET, // property renamed from `network`
})

// Above is equivalent to:
const manager = new WalletManager({
  wallets: [WalletId.DEFLY, WalletId.KIBISIS],
  defaultNetwork: 'mainnet', // string or `NetworkId` enum both valid
  networks: new NetworkConfigBuilder().build() // replaces deprecated `algod` property
})

Adding a custom configuration

const networks = new NetworkConfigBuilder()
  .mainnet({
    algod: {
      token: process.env.MAINNET_TOKEN,
      baseServer: 'https://my-mainnet-node.com'
    }
  })
  .fnet({
    algod: {
      token: process.env.FNET_TOKEN,
      baseServer: 'https://my-fnet-node.com'
    }
  })
  .build()

const manager = new WalletManager({
  wallets: [WalletId.DEFLY, WalletId.KIBISIS],
  defaultNetwork: NetworkId.MAINNET,
  networks,
})

Adding a custom network

const networks = new NetworkConfigBuilder()
  .addNetwork('voi', {
    name: 'Voi Network',
    algod: {
      token: '',
      baseServer: 'https://mainnet-api.voi.nodely.dev',
    },
    isTestnet: false
  })
  .build()

const manager = new WalletManager({
  wallets: [WalletId.KIBISIS],
  defaultNetwork: 'voi',
  networks,
})

⚠️ BREAKING CHANGES: Network configuration now requires using NetworkConfigBuilder instead of the NetworkId-keyed mapped object from v3. While NetworkId is still exported for use with the defaultNetwork property, network configurations must be created using the new builder pattern.

Details

• Add NetworkConfigBuilder for creating and customizing network configurations
• Add support for CAIP-2 chain IDs in network configurations
• Add isTestnet flag to network configurations
• Update all wallet implementations to use new network config system
• Add network property to wallet constructor calls
• Update manager tests to use new network configuration approach
• Add support for custom networks via NetworkConfigBuilder
• Update network-related test assertions
• Add proper genesis hash/ID handling from network configs
• Maintain NetworkId enum for defaultNetwork configuration
• Rename config property network to defaultNetwork
• Rename config property algod to networks

Closes #214