Fix padding and margin for LineLabels and Tooltips #824

[k0psutin]

I wanted to make a PR to check with you @imaNNeo that, this PR is going on the right direction. I still need to make more testing, so a draftish PR.

This PR is for #824 and there were also discussion about adding padding/margin for the tooltips as well.

[codecov]

Codecov Report

Attention: Patch coverage is 93.82716% with 5 lines in your changes are missing coverage. Please review.

Project coverage is 87.41%. Comparing base (930ac12) to head (437af1f).
Report is 14 commits behind head on main.

❗ Current head 437af1f differs from pull request most recent head 3ba03f4. Consider uploading reports for the commit 3ba03f4 to get more accurate results

Files	Patch %	Lines
lib/src/chart/line_chart/line_chart_painter.dart	64.28%	5 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #1587      +/-   ##
==========================================
- Coverage   87.52%   87.41%   -0.11%     
==========================================
  Files          45       46       +1     
  Lines        3078     3092      +14     
==========================================
+ Hits         2694     2703       +9     
- Misses        384      389       +5     

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[k0psutin]

What about these changes? There are no more margin parameters, everything is done by vertical and horizontal offsets. I had to generate mockito files again, so I could write more tests, but I have no idea why it bumped the Mockito version on the comments.

// Mocks generated by Mockito 5.4.4 from annotations

[imaNNeo]

HI, can you please resolve the conflicts?
Then I can review it

[k0psutin]

There were many conflicts, but hopefully everything is okay now. :) Not sure about the changelog format though.