Observe if transactions for decryption keys have been included correctly

[fredo]

Decrypted transactions should be included in the correct order at the top of the block for the expected slot.

If that is not the case, something went wrong.

Either the decryption keys did not arrive in time at the validator or the validator misbehaved.

The following rules are applied:

• Decryption keys are distributed for an expected slot
• The decrypted transactions should be included in the order which they have arrived in the encrypted mempool.
• They should be included at the top of the block
• Invalid transactions will be filtered out by the validator

The metrics system should follow the above rules and notify if something is wrong upon inclusion into the block. I think noticing that a transaction was invalid at the expected slot is out of scope for this issue (It should just be notified that this transaction was not included).

Again we should measure the behavior neutrally and don't make any opinion on who misbehaved.