NickAkhmetov/CAT-859 Remove raw usage of `styled-components`

[NickAkhmetov]

Summary

This PR removes the remaining references to the raw styled-components package. All styling is now handled with @mui/material/styles, and all style.js files have been converted to TypeScript.

Design Documentation/Original Tickets

CAT-859

Testing

Manually confirmed each feature matched as I worked.

Screenshots/Video

N/A - no behavioral changes should occur.

Checklist

• [x] Code follows the project's coding standards
  • [x] Lint checks pass locally
  • [x] New CHANGELOG-your-feature-name-here.md is present in the root directory, describing the change(s) in full sentences.
• [x] Unit tests covering the new feature have been added
• [x] All existing tests pass
• [x] Any relevant documentation in JIRA/Confluence has been updated to reflect the new feature
• [x] Any new functionalities have appropriate analytics functionalities added

Additional Notes

Please specify any additional information or context relevant to this PR.