Refactor toast actions

[lindapaiste]

Merge after #2187

Changes:

• Avoids dispatching sequential actions for setting the toast text and opening the toast. This can be done with one action.
  • setToastText is now removed.
  • showToast is now the only action to dispatch.
• Sets a default timeout of 1500 on the showToast action so that a timeout only needs to be specified when it differs from the default.
• Removes ToastActions from mapDispatchToProps in a bunch of components where it was not actually used, per mapStateToProps and mapDispatchToProps often include unused props #2179
• Rewrites the toast reducer using Redux Toolkit, per Refactoring Redux code: hooks, thunks, and redux-toolkit #2042
  • Reducer actions setToast and hideToast are only used internally for the thunk action showToast.

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