BS api v2: smart contracts

[nikitosing]

Close #6571

Changelog

• add fetching of wallet address from MM before fetching read smart contract methods (can be fetched if you are logged in metamask)
• /addresses/{address_hash}/tokens
• /v2/smart-contracts/{address_hash}
• /v2/smart-contracts/{address_hash}/methods-read (+custom abi)
• /v2/smart-contracts/{address_hash}/methods-write (+custom abi)
• /v2/smart-contracts/{address_hash}/methods-read-proxy
• /v2/smart-contracts/{address_hash}/methods-write-proxy
• /v2/smart-contracts/{address_hash}/query-read-method (+custom abi)
• changed messages format in websockets: internal_transactions, token transfers, transactions
• now /addresses returns 404 if address is not in DB

Checklist for your Pull Request (PR)

• I added an entry to CHANGELOG.md with this PR
• If I added new functionality, I added tests covering it.
• If I fixed a bug, I added a regression test to prevent the bug from silently reappearing again.
• I checked whether I should update the docs and did so by submitting a PR to https://github.com/blockscout/docs
• If I added/changed/removed ENV var, I submitted a PR to https://github.com/blockscout/docs to update the list of env vars at https://github.com/blockscout/docs/blob/master/for-developers/information-and-settings/env-variables.md and I updated the version to master in the Version column. Changes will be reflected in this table: https://docs.blockscout.com/for-developers/information-and-settings/env-variables.
• If I add new indices into DB, I checked, that they are not redundant with PGHero or other tools