`discourse-common` was created in the past to share logic between the
'wizard' app and the main 'discourse' app. Since then, the wizard has
been consolidated into the main app, so the separation of
`discourse-common` is no longer useful.
This commit moves `discourse-common/resolver` into `discourse/resolver`,
adds shims for the imports, and updates existing uses in core.
This will bring significant improvements to install speed & storage requirements. For information on how it may affect you, see https://meta.discourse.org/t/324521
This commit:
- removes the `yarn.lock` and replaces with `pnpm-lock.yaml`
- updates workspaces to pnpm format
- adjusts package dependencies to work with pnpm's stricter resolution strategy
- updates Rails app to load modules from more specific node_modules directories
- adds a `.pnpmfile` which automatically cleans up old yarn-managed `node_modules` directories
- updates various scripts to call `pnpm` instead of `yarn`
- updates patches to use pnpm's native patch system instead of patch-package
- adds a patch for licensee to support pnpm
We rely on yarn workspaces so we don't want people using npm in the repo by accident.
Also updated the required node version to 12+.
~~Not sure about the min yarn version – the latest one could be missing in various CI-like envs, so I might change it yet.~~
Downgraded yarn to ">= 1.21.1" (the oldest of "current" versions, tagged "legacy")
