eslint: Use eslint-config-cozy-app
eslint: Use eslint-config-cozy-app

- Remove standard as we'll be using prettier instead.
- Remove eslint flowtype support since we're already not using it anymore.
- Remove import plugin since it was only needed to support the transpiled
  flow syntax, not the comment-based one.

cozy-labs/cozy-desktop,cozy-labs/cozy-desktop,cozy-labs/cozy-desktop,cozy-labs/cozy-desktop