DT-6904 Remove support for server-side rendering

[optionsome]

Proposed Changes

• Support for SSR is removed
  • Some code etc. related to SSR is removed but there is probably more
• supercluster dependency version had to be downgraded for unit tests to run
  • This is likely due to map code being now always included instead of just in client. When we have better support for ESM, the version can be upgraded again
• feedbackly code is removed as it was unused and complicated context

Pull Request Check List

• A reasonable set of unit tests is included
• Console does not show new warnings/errors
• Changes are documented or they are self explanatory
• This pull request does not have any merge conflicts
• All existing tests pass in CI build

Review

• Read and verify the code changes
• Test the functionality by running the UI locally with all popular browsers available in your platform
• Check that the implementation matches the design, when such one is defined in a Jira issue
• Merge the pull request

[optionsome]

Note, I didn't test with login. It could be that some of the lazy loading, that I've removed, was because of login instead of SSR.