Add metric for propagated transactions size

[Rjected]

Describe the feature

We currently have the following metrics for transactions:

reth/crates/net/network/src/metrics.rs

Lines 56 to 61 in c066aa6

	/// Metrics for the TransactionsManager
	#[derive(Metrics)]
	#[metrics(scope = "network")]
	pub struct TransactionsManagerMetrics {
	/// Total number of propagated transactions
	pub(crate) propagated_transactions: Counter,

The propagated_transactions metric is useful, but does not necessarily give us insight into the network load caused by propagation. We could do that by adding a similar metric that counts the size of the propagated transactions in bytes.

Additional context

No response

[1010adigupta]

would like to work on this with some guidance :)

[mattsse]

cool, this will be possible after #6012 , merging shortly

fyi @emhane

or actually this is unrelated to #6012

reth/crates/net/network/src/transactions.rs

Lines 331 to 334 in 663d877

	fn propagate_transactions(
	&mut self,
	to_propagate: Vec<PropagateTransaction>,
	) -> PropagatedTransactions {

[Rjected]

@1010adigupta have you had time to work on this? do you need any help?

[ameya-deshmukh]

@Rjected I can take this up on the weekend if Adi is cool with it :)

[Rjected]

@Rjected I can take this up on the weekend if Adi is cool with it :)

Sure, if you have time go for it!

[1010adigupta]

@Rjected I can take this up on the weekend if Adi is cool with it :)

yeah sure you can take this up, was not able to look into it much :)

[emhane]

would be really nice if this was grouped by version (eth66 or eth68) and tx type. that can also be a separate issue though.

[onbjerg]

Hey @ameya-deshmukh, any blockers here? Feel free to open a draft PR if you need feedback on direction/have questions :)

[ameya-deshmukh]

hey @onbjerg! no blockers as such but i'm still working on a wip pr. will updated by late friday/early saturday if that works. thanks :)