refactor(getUID): improve performance and simplify logic

[mmr-dev2008]

Description

This PR refactors the getUID function to improve its performance and simplify the code logic.
The function now uses a counter-based approach combined with a DOM uniqueness check, ensuring better performance and readability while maintaining backward compatibility.

Motivation & Context

The original getUID function relied heavily on random number generation, which could result in slower performance in environments with heavy DOM operations. By replacing random generation with a counter-based approach, the function is more efficient, predictable, and easier to understand.
This change was necessary to optimize ID generation in scenarios where a high volume of elements requires unique IDs.

Type of changes

• Refactoring (non-breaking change)

Checklist

• I have read the contributing guidelines.
• My code follows the code style of the project (using npm run lint).
• My change introduces changes to the documentation.
• I have updated the documentation accordingly.
• I have added tests to cover my changes.
• All new and existing tests passed.

Live previews

N/A (No visual changes introduced in this PR).

Related issues

N/A (No reported issues directly related to this change).

[XhmikosR]

Not sure we want the UUID to be predictable and I'd rather not change this without further people chiming in.