refactor project reducers and actions using redux toolkit

[PiyushChandra17]

Associated issue: #2042

Changes:

• First things first removed all the associated constants
• Used createSlice to rewrite the project reducer
• Exported the automatically generated action creator functions from actions/project.js
• Deleted the existing action creator function

I have verified that this pull request:

• has no linting errors (npm run lint)
• has no test errors (npm run test)
• is from a uniquely-named feature branch and is up to date with the develop branch.
• is descriptively named and links to an issue number, i.e. Fixes #123

[lindapaiste]

This isn't right because initialState is a function. It can be written as return initialState().