fix:allow uppercase/lowercase change while renaming a deck

[Fandroid745]

Purpose / Description

The pr fixes the issue of deck already exists warning being displayed while renaming a deck from uppercase to lowercase or vice versa.(e.g:Backend to backend)

Fixes

Fixes a part of #18553

Approach

Updated the conditional in CreateDeckDialog.kt to use ignoreCase so that the checking becomes case-insenstive while renaming a deck to upper/lower.

How Has This Been Tested?

ran the app and verified that the deck already exists warning is not displayed while renaming decks.

Before:

After:

Learning (optional, can help others)

None

Links to blog posts, patterns, libraries or addons used to solve this problem

Checklist

Please, go through these checks before submitting the PR.

• You have a descriptive commit message with a short title (first line, max 50 chars).
• You have commented your code, particularly in hard-to-understand areas
• You have performed a self-review of your own code
• UI changes: include screenshots of all affected screens (in particular showing any new or changed strings)
• UI Changes: You have tested your change using the Google Accessibility Scanner