[Feature]: Send-Many Functions

[setzeus]

Feature - Adding A 'Send-Many' Function To The sBTC Token Contract

1. Description

As pointed out by @friedger, the 'send-many' feature is seen in most sip-10 projects & critical to many projects that need to send tokens to more than one person at a time. Instead of forcing users & contracts to call many times, we should add a 'send-many' function to the existing contract.

1.1 Context & Purpose

As mentioned above, it's not part of sip-10, but most fungible tokens these days include a 'send-many' function for common use-cases; there are a lot of pros & no immediate cons that come to mind in implementing this.

2. Technical Details:

Need to add a single function to the sBTC Token Contract.

2.1 Acceptance Criteria:

• Can send multiple transactions with one contract call

3. Related Issues and Pull Requests (optional):