fix: pick up proper ViewController for KeyboardToolbar when modal is shown

[kirillzyusko]

📜 Description

Fixes incorrect button state if KeyboardToolbar is used inside the modal window.

💡 Motivation and Context

The problem was because of the fact that when modal is shown we still retrieve the rootView. As a result we searched for other inputs (not these that user currently see) and the state of button was broken.

To overcome this problem I decided to search for current active view controller (i. e. modal if it's shown). For that I created an UIApplication extension. It worked, but I noticed one bug (actually e2e tests caught that) - when contact modal is shown and you select the contact, then you move focus to the next input and both arrows should be active. However the state gets broken. It happens because of the fact that we try to search for inputs in modal that has been dismissed. To fix this problem I decided to take only visible modals into consideration and fixed the problem in 095c167

Closes #510

📢 Changelog

iOS

• added new UIApplication extension;
• linked new extension to unit tests project;
• started to use UIApplication.topViewController instead of rootViewController.

🤔 How Has This Been Tested?

tested manually on iPhone 15 Pro + e2e tests.

📸 Screenshots (if appropriate):

📝 Checklist

• CI successfully passed
• I added new mocks and corresponding unit-tests if library API was changed

[github-actions]

📊 Package size report

Current size	Target Size	Difference
145955 bytes	145744 bytes	211 bytes 📈