feat: support testnet4

[zoedberg]

I have rebased the code from #91 since that has merge conflicts and it seems it's dormant since 2 months. I also removed some changes that I think were not necessary (probably there to update rust-bitcoin, which has been already done on the updated tip) and formatted the code with the latest Rust stable version. Moreover I would have renamed the existing Testnet variant to Testnet3, but this is not a decision I should take so let me know if this looks good to you or if you want me to make some changes.

[pseudozach]

what's next for this PR? how can we help get this merged so esplora can have testnet4 support?

[zoedberg]

The PR is waiting for a review. As soon as this gets merged I will open a PR on https://github.com/Blockstream/esplora/ (esplora code is ready but it requires electrs code to be merged into the default branch).

[pseudozach]

lgtm

@RCasatta would you have time to take a look please and thank you 🙏

PR is just adding testnet4 related ports and variables afaict.

[RCasatta]

Concept ACK, some minor comments

checked used port 48332 matches bitcoin core

[RCasatta]

utACK 2163573

I didn't test it actually works on testnet4 but it should

[zoedberg]

@RCasatta if you prefer to test it before merging you can use Blockstream/esplora#570 (just remember to change the clone url in contrib/Dockerfile.base)

[shesek]

One tiny nit, all looks good other than that. Thanks!

[shesek]

I confirmed that d51c0dc matches the changes introduced by cargo fmt (minus one minor difference, probably due to a different cargo version)

$ git checkout new-index # 208491fa40a993a47, zoed/testnet4^^
$ cargo fmt
$ git diff zoed/testnet4^ # d51c0dc2b668d9d7043
diff --git a/src/new_index/mempool.rs b/src/new_index/mempool.rs
index 6d318d2..e11754b 100644
--- a/src/new_index/mempool.rs
+++ b/src/new_index/mempool.rs
@@ -3,7 +3,6 @@ use itertools::{Either, Itertools};
 
 #[cfg(not(feature = "liquid"))]
 use bitcoin::consensus::encode::serialize;
-use electrs_macros::trace;
 #[cfg(feature = "liquid")]
 use elements::{encode::serialize, AssetId};
 
@@ -23,6 +22,7 @@ use crate::new_index::{
 };
 use crate::util::fees::{make_fee_histogram, TxFeeInfo};
 use crate::util::{extract_tx_prevouts, full_hash, get_prev_outpoints, is_spendable, Bytes};
+use electrs_macros::trace;
 
 #[cfg(feature = "liquid")]
 use crate::elements::asset;

[RCasatta]

utACK 117d952

[philippem]

tack