Consider using the general struct 'InboundEvent' to replace the struct 'BTCInboundEvent' used in Bitcoin

[ws4charlie]

Describe the Issue
We've just introduced a general struct InboundEvent for Solana inbound event observation. We should consider unifying the usage of struct InboundEvent and replace the struct BTCInboundEvent used in Bitcoin. The struct is

type InboundEvent struct {
	// SenderChainID is the chain ID of the sender
	SenderChainID int64

	// Sender is the sender address
	Sender string

	// Receiver is the receiver address
	Receiver string

	// TxOrigin is the origin of the transaction
	TxOrigin string

	// Value is the amount of token
	Amount uint64

	// Memo is the memo attached to the inbound
	Memo []byte

	// BlockNumber is the block number of the inbound
	BlockNumber uint64

	// TxHash is the hash of the inbound
	TxHash string

	// Index is the index of the event
	Index uint32

	// CoinType is the coin type of the inbound
	CoinType coin.CoinType

	// Asset is the asset of the inbound
	Asset string
}

Expected Outcome
A description of what outcome you are seeking.