Propose and approve a spend of treasury funds.

- `origin`: Must be `SpendOrigin` with the `Success` value being at least `amount`.
- `amount`: The amount to be transferred from the treasury to the `beneficiary`.
- `beneficiary`: The destination account for the transfer.

NOTE: For record-keeping purposes, the proposer is deemed to be equivalent to the
beneficiary.

- There is a website called polkassembly that lets people vote on different things.
- They have something called referendums, which are like big votes on important topics.
- People can suggest ideas for referendums and then everyone votes on them.
- The website keeps track of the votes and shows the results.
- It's a way for people to have a say in important decisions.

Requested: 0.66 undefined

#255 test