[feature request] coins sdk - support `capabilities` for onchain actions

[azf20]

Currently createCoin calls sendTransaction. This means that there is no way for SDK users to sponsor transactions for their users.

Can we add an optional capabilities argument to createCoin (and other actions, e.g. updating metadata), which if present instead calls sendCalls with a compatibility fallback (link), passing in the capabilities.

I can open a PR is there an appetite to support this.

[iainnash]

You can use createCoinCall to fix this but we can add capabilities pass through as well.