refactor(theming): Remove direct imports of supersetTheme

[msyavuz]

SUMMARY

As part of the theming effort, wherever possible using the useTheme hook instead of directly importing supersetTheme is the preferred way for accesing theme object. This pr aims to clean up leftover uses.

BEFORE/AFTER SCREENSHOTS OR ANIMATED GIF

TESTING INSTRUCTIONS

Run the testing suite.

ADDITIONAL INFORMATION

• [ ] Has associated issue:
• [ ] Required feature flags:
• [ ] Changes UI
• [ ] Includes DB Migration (follow approval process in SIP-59)
  • [ ] Migration is atomic, supports rollback & is backwards-compatible
  • [ ] Confirm DB migration upgrade and downgrade tested
  • [ ] Runtime estimates and downtime expectations provided
• [ ] Introduces new feature or API
• [ ] Removes existing feature or API