[OmniBridge] Implement essential Bridge SDK JS library

[karim-en]

We need to implement essential bridge SDK in Typescript; the library should include basic functions to be able to create and track transfers.

This is just a nominal description of the, it is subject to change during the development if needed.

interface TransferMessage {
  tokenAddress: OmniAddress,
  amount: BigNumber,
  fee: BigNumber,
  nativeFee: BigNumber,
  recipient: OmniAddress,
  message: string | null
}

interface OmniTransfer {
  txId: string,
  nonce: BigNumber,
  transferMessage: TransferMessage
}

function omniTransfer(
  wallet: ethers.Wallet | NearWalletConnection | solWalletAdapter, 
  transferMessage: TransferMessage
): Promise<OmniTransfer>;

function findOmniTransfers(sender: OmniAddress): Promise<OmniTransfer[]>; 
function getFee(sender: OmniAddress, recipient: OmniAddress): Promise<Fee>;
function getTransferStatus(originChain: ChainKind, nonce: BigNumber): Promise<Status>;

function initDeployToken(tokenAddress: OmniAddress, destinationChain: ChainKind): Promise;
function finDeployToken(txId: OmniTranscationId): Promise;
function bindToken(txId: OmniTranscationId): Promise;

Notes:

• The first user of the API will be the bridge web app https://github.com/aurora-is-near/rainbow-bridge-next/pull/241

• There is a Rust SDK that is used by the Omni Relayer https://github.com/Near-One/bridge-sdk-rs

• The previous rainbow bridge implementation is here https://github.com/aurora-is-near/rainbow-bridge-client, but we want to deprecate it.

• Finalisation of the transfers is out of the scope of this issue.

• The findOmniTransfers, getFee, and getStatus are relays on our bridge API provider https://github.com/Near-One/bridge-indexer-rs/tree/master/omni-indexer-endpoint. The endpoint URL for testnet is https://testnet.api.bridge.nearone.org

• initDeployToken: Only tokens that have been deployed on Near can be deployed on other chains. And other chain tokens can be deployed on Near. So to be able to deploy Ethereum Erc20 token on Solana, it should be deployed on Near first

[karim-en]

To init the deployment:

• NEAR: log_metadata
• EVM: logMetadata
• Solana: log_metadata

To finalize it:

• Near: https://github.com/Near-One/omni-bridge/blob/64d77463561400e5d11520813a889ed9a7387c73/near/omni-bridge/src/lib.rs#L605
• EVM: https://github.com/Near-One/omni-bridge/blob/64d77463561400e5d11520813a889ed9a7387c73/evm/src/omni-bridge/contracts/OmniBridge.sol#L76
• Solana: https://github.com/Near-One/omni-bridge/blob/64d77463561400e5d11520813a889ed9a7387c73/solana/bridge_token_factory/programs/bridge_token_factory/src/lib.rs#L41

To bind the deployed token on Near:

• https://github.com/Near-One/omni-bridge/blob/64d77463561400e5d11520813a889ed9a7387c73/near/omni-bridge/src/lib.rs#L719