Improve type safety by removing `any` usage and reducing `as` assertions

[MajorLift]

There are hundreds of instances of any type usage and as assertions spread throughout the metamask-extension, core repo, and other MetaMask libraries.

To uphold coding standards and unlock type-safe feature development for packages undergoing active development, the Shared Libraries team will make an effort to resolve unsafe typings throughout the codebase, prioritizing those encountered during code review.

References

• Related to https://github.com/MetaMask/contributor-docs/47
• Similar https://github.com/MetaMask/core/issues/751
• Closed by:
  • https://github.com/MetaMask/core/issues/3616
  • https://github.com/MetaMask/eslint-config/issues/251