Add ability to use ExtraLinesData in the BarChartData

[NikitaPipita]

Resolves issue #476

• Moved ExtraLinesData class and related classes from line_chart_data.dart to axis_chart_data.dart;
• Moved drawExtraLines function from LineChartPainter class to AxisChartPainter class;
• Added extraLinesData variable to AxisChartData and BarChartData constructors.

[codecov[bot]]

Codecov Report

Merging #975 (5222d1a) into master (544ad7a) will decrease coverage by 0.01%. The diff coverage is 36.66%.

@@            Coverage Diff             @@
##           master     #975      +/-   ##
==========================================
- Coverage   85.02%   85.00%   -0.02%     
==========================================
  Files          42       42              
  Lines        2717     2721       +4     
==========================================
+ Hits         2310     2313       +3     
- Misses        407      408       +1     

Impacted Files	Coverage Δ
.../src/chart/base/axis_chart/axis_chart_painter.dart	67.81% <34.52%> (-31.08%)	:arrow_down:
lib/src/chart/line_chart/line_chart_painter.dart	90.74% <50.00%> (+8.12%)	:arrow_up:
lib/src/chart/bar_chart/bar_chart_painter.dart	93.61% <75.00%> (-0.27%)	:arrow_down:

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[FriendlyNeighbor]

Waiting for this update

[imaNNeo]

Hi. Please resolve conflicts and update your branch. Then I will review it ASAP.

[santiracca]

Hi! any updates when this will be merged?

[JoshMart]

Any reason this PR was closed? I could use this feature on charts I am creating. Perhaps I or someone else can continue this if we know why it was closed?

[imaNNeo]

I closed this PR because the contributor is not responsive.

[JoshMart]

Thanks. I've picked up this work in a fork using these PRs as a starting point, for anyone interested.

[imaNNeo]

It would be great if you mention this PR in your new PR. Thanks