Add dedicated subpool for tracking all blob transactions

[mattsse]

Describe the feature

blob transactions should never have a nonce gap: #4405
and also only be allowed if the sender overdrafts at the time of insert, so they should never initially enter the parked subpool.

A blob tx is pending if it satisfies the base fee and the pending blob fee.
the max_fee_per_blob however does not affect the final tx fee since the blob fee comes from the header (Header::blob_fee).

the max_fee_per_blob is however relevant when evicting transactions, because txs with max_fee_per_blob < pending_blob_fee are not considered pending.

To make it easier to keep track of blob transactions, they should be grouped in a separate subpool, so they can be updated more easily without scanning all transactions

Additional context

No response

[chirag-bgh]

Hey @mattsse , just checking in here if you're going to take this or this is open for contributions. I would like to work on this if so.

[mattsse]

hey, @chirag-bgh

ty, however, I'm already wrapping up this feature, there will be a few followups, so I'll tag you there