Create a new swap function

[Nadar-Suresh]

Swap between XDC to XDCE and vice-versa

Check the difference between XDC and XDCE: https://www.xinfin.org/xdc-xdce

Create an auto swap function that collects the XDC in a wallet and transfers the same number of XDCE (ERC20 Token) in the user's XDCE wallet and if any users transfers XDCE then the XDCE must be collected in XDCE wallet and equallent number of XDC must be transferred to the user's XDC wallet.

This function must be automatic without third person intervention.

XDC Chain Network Tools and Documents for reference: https://xinfin.org/xdc-chain-network-tools-and-documents

AlphaEx exchange have implemented this function. (Refer for idea): https://alphaex.net/trade/XDC-XDCE