<p>This referendum it to unblock the Forex AMM deployment on the Pendulum network by adding the two tokens USDC (AssetHub) and DOT to the token allowance pallet.</p>

This referendum it to unblock the Forex AMM deployment on the Pendulum network by adding the two tokens USDC (AssetHub) and DOT to the token allowance pallet.

Schedule a majority-carries referendum to be tabled next once it is legal to schedule
an external referendum.

The dispatch of this call must be `ExternalMajorityOrigin`.

- `proposal_hash`: The preimage hash of the proposal.

Unlike `external_propose`, blacklisting has no effect on this and it may replace a
pre-scheduled `external_propose` call.

Weight: `O(1)`

Added allowed currencies that possible to use chain extension

# Arguments
* `currencies` - list of currency id allowed to use in chain extension

- **Problem Statement:** Unblock Forex AMM deployment on Pendulum network by adding USDC and DOT tokens.
- **Significance:** Facilitates the deployment of Forex AMM on Pendulum network.
- **Proposed Solution:** Add USDC and DOT tokens to the token allowance pallet.
- **Expected Outcomes:** Enable the deployment of Forex AMM on Pendulum network, enhancing its functionality.

#51 Allowlist USDC and DOT to token allowance pallet