Add ability to burn SLP tokens

[JettScythe]

From what I understand, when users want to burn their SLP tokens they would need to use another wallet or service.
Ideally, we can give our users options to burn a single token or burn all of their tokens from within the wallet.

The minimal-slp-wallet library offers functionality to easily burn tokens from inside the wallet. Examples can be viewed here: https://github.com/Permissionless-Software-Foundation/minimal-slp-wallet/blob/master/examples/burn-some-tokens.js & https://github.com/Permissionless-Software-Foundation/minimal-slp-wallet/blob/master/examples/burn-all-tokens.js