Refactor bp::Network into ChainParams

[dr-orlovsky]

We need to support wide range of networks (including Liquid, LN) and create a foundation for generic asset concept (that includes chain-based assets and RGB assets).

Draft concept:

/// P2P network magic number: prefix identifying network on which node operates
pub type P2pMagic = u32;
/// Magic number prefixing Pubkey or Prvkey data according to BIP32 spec
pub type Bip32Magic = u32;

#[derive(Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Hash)]
#[non_exhaustive]
#[repr(u8)]
pub enum ChainFormat {
    Bitcoin = 0,
    Elements = 1,
}

#[derive(Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Hash)]
#[repr(u8)]
pub enum AssetLayer {
    Layer1and2,
    Layer2and3,
}

#[derive(Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Hash)]
pub struct AssetParams {
    pub ticker: &'static str,
    pub unit_of_accounting: &'static str,
    pub indivisible_unit: &'static str,
    pub divisibility: u64,
    pub asset_id: AssetId,
}

#[derive(Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Hash)]
pub struct ChainParams {
    pub name: &'static str,
    pub p2p_magic: P2pMagic,
    pub genesis_hash: BlockHash,
    pub bip32_pubkey: Bip32Magic,
    pub bip32_prvkey: Bip32Magic,
    pub bip70_name: &'static str,
    pub bip173_prefix: &'static str,
    pub p2p_port: u16,
    pub rpc_port: u16,
    pub ln_height: u32,
    pub format: ChainFormat,
    pub dust_limit: u64,
    pub native_asset: AssetParams,
    pub testnet: bool,
    pub pow: bool,
}

/// A set of recommended standard networks. Differs from bitcoin::Network in
/// ability to support non-standard and non-predefined networks
#[derive(Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Hash)]
#[non_exhaustive]
#[repr(u32)]
pub enum Chains {
    Mainnet,
    Testnet3,
    Regtest(BlockHash),
    Signet,
    SignetPrivate(BlockHash),
    LiquidV1,
    Other(ChainParams),
}