Add KFocusTrap and use it in KModal

[lokesh-sagi125]

Description

copy FocusTrap from kolibri into KFocusTrap in the KDS and use it in the KModal

Issue addressed

Add KFocusTrap and use it in KModal #746

Addresses #746

Before/after screenshots

before:-
https://github.com/user-attachments/assets/c38be827-683f-4d45-86b2-e845a2193744

after:-
https://github.com/user-attachments/assets/b5b27ea8-0d12-42fa-8fff-2de408a4eeb3

Changelog

• Description: Summary of change(s)
• Products impact: Choose from - none (for internal updates) / bugfix / new API / updated API / removed API. If it's 'none', use "-" for all items below to indicate they are not relevant.
• Addresses: Link(s) to GH issue(s) addressed. Include KDS links as well as links to related issues in a consumer product repository too.
• Components: Affected public KDS component. Do not include internal sub-components or documentation components.
• Breaking: Will this change break something in a consumer? Choose from: yes / no
• Impacts a11y: Does this change improve a11y or adds new features that can be used to improve it? Choose from: yes / no
• Guidance: Why and how to introduce this update to a consumer? Required for breaking changes, appreciated for changes with a11y impact, and welcomed for non-breaking changes when relevant.

[lokesh-sagi125]

hey @akolson @MisRob can you review this code for me , i have attached the before and after videos.i have run lint-fix multiple times and tried adding and removing an extra line but couldn't fix it .