Txpool v2 features for futures connections with other modules

[AurelienFT]

REVIEWER NOTE: Review #2193 first for context

Linked Issues/PRs

Closes #2187

Description

Block producer

Existing	New
select_transactions(max_gas)	select_transactions(max_gas)

PoA

Existing	New
total_consumable_gas()	Nothing (unused)
transaction_status_events()	Replaced by new_txs_notifier reason
pending_number()	Not used anymore after transaction_status_events() change
remove_txs()	Can be remove because it's used to delete transactions that are already deleted

Block Importer

Existing	New
Stream with blockEvents	Stream with block events

P2P

Existing	New
gossiped_tx_stream	tx_from_p2p_stream
new_tx_gossip_subscription	new_peers_subscribed_stream
broadcast_transaction	broadcast_transaction
get_tx_ids	get_tx_ids
get_txs	get_txs
notify_gossip_transaction_validity	notify_gossip_transaction_validity

GraphQL API

Existing	New
transaction	transaction
tx_update_subscribe	tx_update_subscribe

Also add TTL management

Checklist

• Breaking changes are clearly marked as such in the PR description and changelog
• New behavior is reflected in tests
• The specification matches the implemented behavior (link update PR if changes are needed)

Before requesting review

• I have reviewed the code myself
• I have created follow-up issues caused by this PR and linked them here