Issue:225 Feature: Integrating World Clock in UAC

[VatsalJain2004]

### Description
Integrated World Clock Functionality.. quite common in our mobile's default clock apps

Proposed Changes

Added following Directories:
UAC
> app
> modules
> citySelection
>worldClockPage

Fixes #225

Screenshots

Checklist

• [✅] Tests have been added or updated to cover the changes
• [✅] Code follows the established coding style guidelines
• [✅] Has Search Functionality as Promised
• [✅] Has Vast list from which user can select a International GMT

[Ni1esh-Yadav]

Hello @VatsalJain2004 I was going through this pr, I would recommend made some slight changes like use the font style that has been used on other screens this will increase the user experience and overall ui will look better.Also try to adjust bottom navigation bar as user will not be able to interpret just by the icon so label should be pre-visible Thank you.