feat: banner, add optional callback for on animation complete

[daniel112]

Summary

After using the Banner component, for better flexibility for customization, I find that it could be useful for consumers to hook into the callback for when the default animation completes.
i.e doing some action after the banner is completely gone as opposed to during animation after setting visible=false

Test plan

I've modified the Banner example to log out whenever it completes the open/close animation. If that is not a preferred modification to examples then you can test by:

1. modifying BannerExample.tsx for onAnimateShowFinish and/or onAnimateHideFinish callbacks

        <Banner
          ...otherprops
          onAnimateShowFinish={() => console.log('Completed opening animation')}
          onAnimateHideFinish={() => console.log('Completed closing animation')}
        >

      </Banner>

2. Run the example app
3. toggle the Banner show/hide
4. see that it logs out at the appropriate time

[callstack-bot]

Hey @daniel112, thank you for your pull request 🤗. The documentation from this branch can be viewed here.

[github-actions]

Hello 👋, this pull request has been open for more than 2 months with no activity on it. If you think this is still necessary with the latest version, please comment and ping a maintainer to get this reviewed, otherwise it will be closed automatically in 7 days.

[daniel112]

@brunohkbx

[lukewalczak]

I would rename those

[brunohkbx]

hey @daniel112 can you please fix the conflicts?

[daniel112]

hey @daniel112 can you please fix the conflicts?

done!