Add support for ERC-20 "Token Bonds"

I propose a new bond type that can lock up any ERC-20 token. Existing "Liquidity Bonds" lock Uniswap LP combined with an equal amount of SYNC.

This new "Token bond" could wrap any ERC token into a bond in addition to SYNC. The bond would follow similar mechanics of existing bond, yet just contain SYNC / ERC-20 tokens instead of LP. This frees the user from Uniswap and from the risk on Impairment loss.

Once this new bond type exists, future use cases are opened up:

Bond Staking, Token NFTs, Forced Hodl.

For example if a user stakes 10,000 SWAP tokens in the SWAP staking portal, he is granted rewards for staking his SWAP. However this lock is only 7 days. The user can un stake at anytime and withdraw in 7 days.

A SWAP Token Bond could be added to the staking pool and earn additional rewards based on the lock time.

This would incentivize more users to create long term bonds and help projects by ensuring longer duration locks.

Perhaps we could work with the TrustSwap team to build out this use case, once we can offer "ERC-20 Token Bonds"