fix: unappliedSlashes per Era

[Imod7]

Description

This PR is a continuation/additional fix of the previous fix/PR #1868

Changes

• We are now taking into account the era key and we are iterating through the slashes per era. Consequently, the era info is added in the response.
• The correct type of the unappliedSlashes is UnappliedSlashes where we have

  UnappliedSlash<T>,
  OptionQuery,
  

• So, the information for each slash is an Option which we need to check and unwrap.
• The correct type from pj-api is PalletStakingAsyncUnappliedSlash.

Testing

You can test this change:

• with a local instance of Sidecar with .env file:

SAS_SUBSTRATE_URL=wss://kusama-asset-hub-rpc.polkadot.io
SAS_SUBSTRATE_MULTI_CHAIN_URL='[{"url":"wss://kusama-rpc.polkadot.io","type":"relay"}]'

• and querying the endpoint http://127.0.0.1:8080/pallets/staking/progress
• which returns

 "unappliedSlashes": [
    {
      "era": "9027",
      "validator": "D5aAp1y8XfkrmtPqsGFZtCjJrPZqKrsG2ceSha846jy6RMU",
      "own": "3289142260",
      "others": [
        [
          "G1rrUNQSk7CjjEmLSGcpNu72tVtyzbWdUvgmSer9eBitXWf",
          "5213796174"
        ],
        [
          "G4RasQNUjgkXkdCuW2zgMJPcjZijaTmkJixb3oMxg9eiHng",
          "58511039826"
        ],
        ....
      ],
      "reporter": "Ed1xXhwva7tsK6sY5WnRQNVQ5bXC2kNbkpbU1EhjPZy4Cb6",
      "payout": "7407060837"
    }
  ],

Credits

Credits and thanks to @Ank4n for pinpointing the correct type in p-sdk and recommending to iterate by era 💯

[TarikGul]

👍