support monorepo structure (npm 7 / lerna etc..)

[jony89]

patch-package currently does not support npm7 workspaces or any monorepo structure.

This is a monorepo structure for example:

package.json
apps
  app1
   - package.json
  app2
   - package.json

npm 7 installs packages from app1 that exist only in app1, for example, within the root node_modules and not in app1/node_modules, thus while running npx patch-package my-package I get the error "my-package does not exist / not found".

So in order to support that we need to check if the package does exist in app1/package.json to keep looking for the package but in the node_modules folder that is higher in the hierarchy and has package.json as well.

[jony89]

duplicates #277