Eslint config cleanup (#1424)

* Replace deprecated ESLint rules

See: https://eslint.org/docs/rules/#deprecated

* ESLint: switch `0`, `1` and `2` to `off`, `warn` and `error`.

* Simplify no-async rule

* Cleanup disable comments

* Switch ESLint config to YAML

See: https://eslint.org/docs/user-guide/configuring#configuration-file-formats

Author: IvanGoncharov