feat: [AHM] - Add AH Next Westend chain

[Imod7]

Description

Part of #1488

One of the initial phases of the Asset Hub Migration process is the addition of the Asset Hub Next Westend chain where a test migration will occur. In this PR we are adding support for this chain to provide a testing environment:

• for external teams using Sidecar so they can validate their code functionality against the migrated pallets/endpoints.
• for Sidecar maintainers so they can verify the migrated endpoints functionalities and completeness. This PR can also serve as a template, as the same changes will also be applied to both Kusama and Polkadot migrations.

Code Changes

A new controllers configuration is added for the Asset Hub Next Westend chain called assetHubNextWestendControllers.ts. This Controller is a copy of assetHubWestendControllers.ts file but with the following additional Controllers :

• from westendControllers:
  • AccountsStakingInfo
  • AccountsStakingPayouts
  • AccountsVestingInfo
  • PalletsNominationPools
  • PalletsStakingProgress
  • PalletsStakingValidators
• from defaultControllers:
  • PalletsOnGoingReferenda
  • PalletsStorage

The namings & spec-name for the test chain were chosen based on the details and changes found in this PR.

Notes

The Controllers added were chosen based on:

• the AHM document where the systems (Staking, Governance (including Treasury), Balances) to be migrated are mentioned.
• the specific pallets mentioned in the list of Pallets with status "Remove from Relay - Setup New on AH" such as pallet_stakingand pallet_vesting.

Testing

In order to test properly & merge this PR, we need to wait until the test chain is live and we have a public endpoint to connect to.

[IkerAlus]

LGTM

[seadanda]

Can we merge this ahead of the chain going live or does this need to be timed?

[Imod7]

Can we merge this ahead of the chain going live or does this need to be timed?

We can merge this ahead of the chain going live. I am merging in a few minutes.