Scheduled Transactions: Simplify Priority Assignment for better performance

Issue To Be Solved

Based on the performance analysis we did for Scheduled Transactions, the current setup of shared limits for priorities is unnecessarily complex and uses computation that should not be used. We want to make it more straightforward and easy to understand

Suggest A Solution

• Each priority gets its own bucket and there is no shared limit
• Medium and Low priority still look for future timestamps if the requested one is full
• Low priority transactions will no longer be kicked out and rescheduled if a higher priority comes to the same timestamp
• We may need to lower fee multipliers since this proposal lowers the assurances for high priority and medium that they would kick out low priority transactions.
• We can use the existing nested fields for the priorities, so this just changes how the transactions and efforts are allocated

Considerations

• Ensure that the upgrade will not cause any state to get out of whack
• Test performance to see what improvements there are