Default tooltip index is decided through selector, not reading DOM

[PavelVanecek]

Description

This removed some of the test failures, will continue in next PR.

Related Issue

https://github.com/recharts/recharts/discussions/3717

Motivation and Context

Remove direct DOM access

How Has This Been Tested?

npm test

Screenshots (if appropriate):

Types of changes

• [ ] Bug fix (non-breaking change which fixes an issue)
• [ ] New feature (non-breaking change which adds functionality)
• [ ] Breaking change (fix or feature that would cause existing functionality to change)

Checklist:

• [ ] My change requires a change to the documentation.
• [ ] I have updated the documentation accordingly.
• [ ] I have added tests to cover my changes.
• [ ] I have added a storybook story or extended an existing story to show my changes

[codecov[bot]]

Codecov Report

All modified and coverable lines are covered by tests :white_check_mark:

Project coverage is 95.59%. Comparing base (74fa2a3) to head (eb67702).

Additional details and impacted files

```diff @@ Coverage Diff @@ ## 3.x #4543 +/- ## ========================================== + Coverage 95.58% 95.59% +0.01% ========================================== Files 116 116 Lines 22365 22430 +65 Branches 3073 3080 +7 ========================================== + Hits 21378 21443 +65 Misses 981 981 Partials 6 6 ```

:umbrella: View full report in Codecov by Sentry.
:loudspeaker: Have feedback on the report? Share it here.