Support of EIP-1155 compatible fungible tokens

[akolotov]

Consider to support fungible tokens implemented with the EIP-1155 standard.

Several notes:

1. Both single mode and batch mode must be supported.
2. Consider to have more than one minter allowed for the bridged token (e.g. through an intermediate minter contract). The main idea is to allow FT OB and NFT OB mint tokens on the same EIP1155 token contract.
3. Consider the following implementation of meta-transactions

The set of changes could be shared with omni/omnibridge-nft#24.