1052437: Fixed the warnings in the Toolkit Charts.

[Yokesh-SF4393]

Bug description

Need to fix the Code analyzer warnings, nullable warnings and all other warnings for toolkit chart component.

Root cause

Need to clear the warnings in Toolkit charts component, to make the component more stable.

Solution description

Fixed CA1031, CA1508, CA8600, CA8601, CS8604, CS8602 warnings.
Overall count: 7707
Pending count: 7517
Cleared: 190

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

Post the output screenshots if a UI is affected or added due to this bug.

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

[github-actions]

CI Summary

Job	Status
bUnit (.NET 8 / 9 / 10)	✅ Passed
Playwright	✅ Passed
NuGet vulnerability scan	✅ Passed
ESLint security	✅ Passed
XSS / unsafe markup scan	✅ Passed

Overall: ✅ All checks passed