Migrate from npm to yarn

[k1rill-fedoseev]

I noticed that yarn package manager works much faster than the default npm. Also, yarn is used in the monorepo, so I propose to use it in this repo as well.

While changes delta in this PR is insane, there are only a few things were done:

• Move ./contracts/* to ./contracts/contracts/*, update import paths in deploy scripts.
• Add contracts, deploy, upgrade workspaces to the root package.json
• Remove npm's package-lock.json files, generate yarn.lock by running yarn install. As a side effect, this caused a lot of dependency updates.
• Enable linting for ./deploy and ./upgrade, it was already configured previously, but was not run.
• Run yarn lint:js:fix and yarn lint:sol:fix to fix appeared lint errors.
• Replace usages of npm with yarn commands in docs, scripts, Dockerfiles, etc.

[akolotov]

Could you share ideas why previously the lint does not require such changes for the contracts?

[akolotov]

why is it require to move contracts to ./contracts/contracts/ instead of ./contracts?

[k1rill-fedoseev]

Could you share ideas why previously the lint does not require such changes for the contracts?

I think some linting rules were changed or added to the new version of solhint.

why is it require to move contracts to ./contracts/contracts/ instead of ./contracts?

That is the recommended way to use yarn workspaces, to keep each workspace code and dependencies in its own directory.