Report for unconfirmed sortition transactions

[b00f]

Description

Some users are complaining about not getting into the committee. Since entering the committee is a random process, it makes sense that some validators might experience delays in joining.

However, to ensure that validators don't miss any chance to enter the committee, we should have a report of unconfirmed sortition transactions.

The process will be as follows:

1. Once a sortition transaction is broadcasted, we keep the hash in memory (like a map).
2. When it is confirmed, we remove it from the map.

The size of the map will represent the number of unconfirmed sortition transactions.