refactor(ios): change Ti.UI.TabbedBar to use UITabBar

[jquick-axway]

JIRA:
https://jira.appcelerator.org/browse/TIMOB-28373

Summary:

• This changes Ti.UI.TabbedBar to use a tab bar instead of a segmented control.
• Titanium 10.0.0's new Ti.UI.OptionBar is now used to display a segmented control on iOS. See: TIMOB-28317
• Intention is that a widget named TabbedBar should show tabs, like it does on Android, and allow app devs to layout their own tab group like user interface.

Test:

1. Build and run TabbedBarTest.js attached to TIMOB-28373 on iOS.
2. Verify that the app shows tabs as shown in the screenshot above.
3. Tap on the 2nd tab of every bar and verify the following gets logged.
   @@@ button click index: 1

[build]

	Fails
🚫	Tests have failed, see below for more information.
🚫	Test suite crashed on iOS simulator. Please see the crash log for more details.
🚫	🔬 There are library changes, but no changes to the unit tests. That's OK as long as you're refactoring existing code, but will require an admin to merge this PR. Please see README.md#unit-tests for docs on unit testing.

	Warnings
⚠️	This PR has milestone set to 10.0.0, but the version defined in package.json is 10.1.0 Please either: - Update the milestone on the PR - Update the version in package.json - Hold the PR to be merged later after a release and version bump on this branch

	Messages
📖	✊ The commits in this PR match our conventions! Feel free to Rebase and Merge this PR when ready.
📖	❌ 2 tests have failed There are 2 tests failing and 682 skipped out of 11676 total tests.

Tests:

Classname	Name	Time	Error
android.emulator.Titanium.UI.View	"after all" hook (5.0.2)	20.542	Error: timeout of 10000ms exceeded at Titanium.<anonymous> (/ti-mocha.js:6535:53723)
android.emulator.Titanium.UI.View	"after each" hook (5.0.2)	10.533	Error: timeout of 10000ms exceeded at Titanium.<anonymous> (/ti-mocha.js:6535:53723)

Generated by 🚫 dangerJS against 039318e

[hansemannn]

Please reconsider if this is really a good idea. The UITabBar is a top-level element on iOS and should not be added to a view directly. It's probably even causing App Store rejections and can be easily overseen by developers that have larger apps and upgrade to SDK 10 (which, in terms of the recent news) will not really help developers.

[vijaysingh-axway]

1. As per Apple doc here, UITabBar is typically used in conjunction with UITabBarController. In titanium Ti.UI.TabGroup is used to implement UITabBarController.
2. I don't think adding UITabBar as standalone component will cause Appstore rejection.
3. Do we want to make breaking change for this, which people are using from long and I think no one is asking for this?

[hansemannn]

@vijaysingh-axway Regarding (2), see this link for reference, especially:

Use a tab bar strictly for navigation. Don’t use tab bar buttons to enable actions. If you need to provide controls that act on elements in the current view, use a toolbar instead.

As well as the fact that button-only tabbed bars (which is the only default right now) will cause major display issues, because UITab's are meant to have an icon and without it, the title will be displayed at the bottom (see screenshot above).

[jquick-axway]

No one here is suggesting that UITabBar should be used as a toolbar or as a segmented control replacement. The main point here is that Ti.UI.TabbedBar is misnamed for the native component currently used on iOS. The solution is to create a new Ti.UI.OptionBar to show a segmented control (already merged into Titanium 10.0.0) and change Ti.UI.TabbedBar to use UITabBar so app developers can implement their own custom tab group like interface.

If you feel this is controversial, then I can close this PR for 10.0.0. This means iOS will use a native UISegmentedControl for both Ti.UI.TabbedBar and Ti.UI.OptionsBar.

On Android, Ti.UI.TabbedBar uses the native TabLayout and BottomNavigationView. The new Ti.UI.OptionBar uses the native MaterialToggleButtonGroup. We're not changing the Android side. The native widgets being used on Android make sense.