104901: Provided HighContrast theme support for Chart

[Keerthivasan-Ramamoorthy]

Bug description

Need to provide support for the HighContrast theme for charts.

Root cause

The Accessibility testing lacks for high contrast support.

Solution description

Provided high contrast theme support for blazor toolkit charts with reference to the blazor charts.

Code Studio usage(Mandatory)

• Code Studio used in this PR/MR?

  • Yes
  • No

• If Yes: Primary use (choose one)

  • Generate new code
  • Refactor/improve existing code
  • Tests
  • Bug fix / debugging help
  • Docs / comments
  • Review assistance (explanations/summaries)
  • Other:

• Outcome

  • Saved time
  • Neutral
  • Cost time

• If “Cost time” explain in short (1 or 2 lines):

Impact assessment

• Low - Affects a single feature with minimal user impact
• Medium - Affects multiple features or has moderate user impact
• High - Critical functionality or significant user impact

Reason for not identifying earlier

Provide the reason for not identifying the bug earlier.

Areas tested against this fix

• Tested using standard test cases
• Tested against feature matrix. Centralized location
• NA

Breaking changes

• Yes (Tag breaking-issue)
• No

If yes, provide breaking commit details link and migration guidance.

Regression testing

• Verified fix doesn't reintroduce previous bugs
• Checked edge cases and error scenarios

Action taken to prevent recurrence

• Added/updated unit tests
• Other (specify): _________________
• NA

Automation status

• BUnit (provide PR link: _________________)
• Playwight (provide PR link: _________________)
• NA

Cross-platform verification

• Blazor Server
• Blazor WASM
• NA

Related issues

Is this issue present in EJ2 or other components?

• Resolved in EJ2 (PR link: _________________)
• Created task for EJ2 (Task link: _________________)
• Needs attention in other components (tag needs-attention-coreteam)
• NA

Output screenshots

API changes

• New API added (API Review task link: _________________)
• Existing API renamed/modified (API Review task link: _________________)
• No API changes

Performance verification

• Verified no memory leaks introduced
• Verified no performance degradation
• Not applicable

Reviewer Checklist

• Reviewed the provided Code Studio usages related information.
• Code changes follow component guidelines
• All provided information reviewed and verified
• Solution addresses the root cause effectively