feat: enhance icon tags with British variants, synonyms, and cleanup (#2058)

## Description
Applied the modifications as recommended in this comment:
#2057 (comment)

## Motivation and Context
Closes #2057 

## How Has This Been Tested?
Manually tested

## Screenshots (if appropriate):

## Types of changes
<!--- What types of changes does your code introduce? Put an `x` in all
the boxes that apply: -->
- [ ] Bug fix (non-breaking change which fixes an issue)
- [x] New feature (non-breaking change which adds functionality)
- [ ] Breaking change (fix or feature that would cause existing
functionality to change)

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Co-authored-by: Marcel Wagner <marcelwagner@microsoft.com>

Author: Zakariathr22