Merge branch 'rel-2.0.0'

changelog update

fix api call

upgraded to null safety

remove unused code

drop firebase auth and firestore crud support

Merge tag 'v1.4.0' into develop

Merge branch 'release/1.4.0'

changelog, version upgrade and usage for gen command

Merge branch 'feature/refactor' into develop

fixing multiple times plugin adding problem

check if already exists

check for if plugin already exists

refactoring making everything private

generate features and core folders for modified TDD structure