Scheduled Txs: Optimize Schedule

[joshuahannan]

Issue To Be Solved

Transactions that schedule other transactions seem to take longer to execute than expected. We need to make some performance improvements.

Suggest A Solution

• Recommend that transactions don't use estimate() to get the cost of the transaction because it is redundant. They should use calculateFee instead.
• Update addTransaction to use references instead of copying
• Still looking for more