Port over all api.query.<pallet>.<method>.at() -> api.at() historic api

[TarikGul]

All services that use api.query...at() will be deprecated via affa6ab in polkadot-js. It's important to refactor each service to now use a api.at() historicApi.

List of services to refactor:

• BlocksService [fix(BlocksService): refactor api.derive for performance, and add historicApi to BlocksService #699]
• AccountAssetsBalanceInfoService [fix(AccountsAssets): historicApi for AccountsAssets, bug fixes, error handling, e2e-tests #721]
• AccountsBalanceInfoService [fix: update accounts balance-info and vesting-info to use historicApi #709]
• AccountsStakingInfoService [fix(StakingInfo): add historicApi to staking-info #741]
• AccountsStakingPayoutsService [fix: staking payouts historicApi, and add tests #762]
• AccountsVestingInfoService [fix: update accounts balance-info and vesting-info to use historicApi #709]
• PalletsStakingProgressService [fix: pallets staking progress historicApi #761]
• PalletsStorageService [fix!: pallet storage metadataV14  #710]
• ParasService [fix(ParasService): adjust endpoint to use historicApi, fix endingOffset bug #735]
• [ readjust mockApi, and historicApi for testing env [fix(tests): restructure mockApi tests to integrate with historical api #702]

rel: #697

[TarikGul]

Before I can go any further with this issue, #702 needs to be merged

[jacogr]

Just a note - these won't be removed anytime soon (certainly not in the mids of the 6.x range). The reality is that api.at is cleaner and does a whole host of things better, i.e. giving you an actual instance at that point, correctly decorated. Additionally this is used everywhere, so it certainly won't be dropped soon (probably will still live in the 7.x version as well), generally don't like breaking other people's code.

Currently the older versions now use api.at internally so it should yield less breakages, which with the new metadata + types is quite tricky with the (now deprecated) versions.

[TarikGul]

Okay sweet, good to know. I Appreciate the explanation. That helps a lot because I currently see some instances where I might have to leave the api.query.*.*.at in for the time being. I have actually been finding api.at to be a really great upgrade in general as well, having the centralized source of truth in the api is such an incredibly useful feature.