Upgrade to Polkadot v0.9.42

Description

This is the upgrade from polkadot-v0.9.32 to polkadot-v0.9.42 that brings several breaking changes:

• Babe refactoring: https://github.com/paritytech/substrate/pull/13883
• Balances refactoring: https://github.com/paritytech/substrate/pull/12951
• Offences refactoring.
• DustRemoval type is incompatible with Treasury.

Fixed errors

• TotalIssuance was not initialized correctly, 79d0d42b and 9b94d8fb.

Will need refactoring

• The pallet duniter-account will need to be refactored for a better integration with the new AccountData 13ab4150.
• Some scenarios (like 9d0c7835) are now deprecated due to the refactoring of the pallet balances that adds checks and providers limiting extrinsics usage.
• The providers, consumers, and sufficients counts need some refactoring to be better integrated with the pallet balances own new counts. 007aba57 introduces some workarounds to get the tests passing (with non blocking errors due to the providers count), but an overall spec reviewing and refactoring will be needed.

Changed (dependencies)

• Upgraded Duniter Substrate.
• Upgraded Duniter Subxt.

Changed

• Updated weight files.
• Updated tests with new Subxt API.
• Changed Babe sealing and RPC according to Babe refactoring.
• Updated pallet configurations according to Offences refactoring.
• Updated xtask.

Added

• Added DustHandle to convert the dust from pallet balances and add it to the treasury f357c9ec.

Deprecated

• One pallet balances benchmark needed https://github.com/duniter/substrate/commit/c36ab4f32454318a47777b24b6533c44121fc10b because pallet duniter-account was adding another provider, 007aba57 workaround deprecated this behavior.

To discuss

• Values setting for HoldIdentifier, FreezeIdentifier, MaxHolds, MaxFreezes, and particularly MaxSetIdSessionEntries.

docs/dev/upgrade-substrate.md

@@ -5,8 +5,10 @@ We need to keep up to date with Substrate. Here is an empirical guide.
 Let's say for the example that we want to upgrade from `v0.9.26` to `v0.9.32`.
 
 ## Upgrade Substrate fork
-
-TBD (only Élois has done this for now)
+1. Checkout the latest Substrate Polkadot branch `polkadot-v0.9.xy` in [our Substrate](https://github.com/duniter/substrate/)
+2. Create a new branch `duniter-substrate-v0.9.xy`
+3. Cherry-pick `3ad5e1a1fdac5398d4911272a34e1f16c1bdd8f0` and `3ad5e1a1fdac5398d4911272a34e1f16c1bdd8f0`
+4. Run `cargo check` to check the cherry-picking
 
 ## Upgrade Subxt fork