Summary

This PR leverages the redux store work done previously and changes the way we save the state of the flyout type (push vs overlay). Instead of using hooks, this PR is now using redux. In the previous PR we had nested the store information under a new top level store state called panels. This PR introduces a another new top level state called ui. This new state is used to store the pushVsOverlay state, and will be used in the next PR for all the new resized widths logic.

Originally, the pushVsOverlay values were saved for each flyout (using the urlKey). After discussing this (see comments below), the functionality now saves a unique value that will be applied to all expandable flyouts.
Also the value changed by the user is saved in local storage (only if the push vs overlay) option is enabled. The local storage key is expandableFlyout.ui and we store a simple object:

{
  pushVsOverlay: string;
}

This object will see more properties in the next PR that will add all the resizable logic.

Here are the main changes introduced here:

• introduced the new ui top level slice of state
• move the push vs overlay logic to redux, hence:
  • create a new uiReducer
  • create a new middleware to push to local storage the values selected by the user
  • delete the old pushVsOverlay hook
  • update the related components to use redux
• small performance improvement, avoid the SettingsMenu component to render if unnecessary
• update all the unit tests

None of the changes impact UI and the actual push vs overlay functionality remains unchanged. These are just code improvements!

Checklist

• Unit or functional tests were updated or added to match the most common scenarios

Will help #182526