Add more tab tray customizations

[miDeb]

Adds an option to bring back the fab and to select a direction to open the tab tray.
@abhijitvalluri could you review? :)
The default is still the same as before.
Maybe someone could suggest better strings for the settings? I don't think they're currently very good.
screenshots:

Pull Request checklist

• Tests: This PR includes thorough tests or an explanation of why it does not
• Screenshots: This PR includes screenshots or GIFs of the changes made or an explanation of why it does not
• Accessibility: The code in this PR follows accessibility best practices or does not include any user facing features. In addition, it includes a screenshot of a successful accessibility scan to ensure no new defects are added to the product.

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[abhijitvalluri]

Dang it, I am working on the same set of features and some more actually! :D How do we go about resolving conflicts?

[miDeb]

Hey, what a coincidence! If you are working on a bigger set of changes, it would probably make more sense to take yours i guess. But obviously feel free to take stuff from my pr if you haven't yet implemented them

[abhijitvalluri]

@miDeb I finally created my PR #65! It took a lot more time than I expected due to some frustrating issues getting all the functionality and behaviour just right for all the configuration options. Getting scrollToTab() in TabTrayView.kt to work correctly took a lot of effort and frustrating tweaking, for example! But it is here finally, and I incorporated all your customization options. I copied over your top FAB layout. Check it out!

[miDeb]

Very cool!