Refactor: src/screens/BlockUser

[VanshikaSabharwal]

Is your feature request related to a problem? Please describe.

This file is currently tested using Jest. As part of our migration to Vitest, we need to refactor this file's test cases to align with Vitest's syntax and features.

Acceptance Criteria

Replace Jest-specific functions and mocks with Vitest equivalents and rename from test.tsx to spec.tsx
Ensure all tests in src/components/AddOn/support/components/SidePanel/SidePanel.test.tsx pass after migration using npm run test:vitest
Maintain the test coverage for the file as 100% after migration
Upload a video or photo for this specific file coverage is 100% in the PR description
Additional Context

Refer to the merged PR for the base Vitest configuration:
https://github.com/PalisadoesFoundation/talawa-admin/pull/2457/files#diff-9a5a35cf8d7f02b2bba90905714b762560579c4789e9eb4cebb4607980aa3d93
Vitest documentation:
https://vitest.dev/
Potential internship candidates
Please read this if you are planning to apply for a Palisadoes Foundation internship

PalisadoesFoundation/talawa#359

[github-actions]

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