Add text field to range annotations

[Shunt22]

We can use something like this to add text for horizontal and vertical range annotations.
Refrering to: #522.
Usage:

VerticalRangeAnnotation(
  horizontalPadding: 0,
  verticalPadding: 0,
  text: "Hello world",
  style: TextStyle(),
  rotation: 90,
  x1: 0,
  x2: 10,
  color: Colors.red,
 )
                                   

[imaNNeo]

When I tried to add it in our line chart sample 8, it didn't work as I expected. So the text is somewhere else

[Shunt22]

I've made it more clearer.

[codecov]

Codecov Report

Attention: Patch coverage is 59.09091% with 9 lines in your changes missing coverage. Please review.

Project coverage is 92.21%. Comparing base (195a41c) to head (c9a201e).
Report is 56 commits behind head on main.

Files with missing lines	Patch %	Lines
.../src/chart/base/axis_chart/axis_chart_painter.dart	59.09%	9 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #1865      +/-   ##
==========================================
- Coverage   92.51%   92.21%   -0.31%     
==========================================
  Files          46       46              
  Lines        3341     3366      +25     
==========================================
+ Hits         3091     3104      +13     
- Misses        250      262      +12     

Flag	Coverage Δ
flutter	92.21% <59.09%> (-0.31%)	⬇️

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[imaNNeo]

Hi, thanks for the update. Functionality seems to work well! Good job.
But there are still some concerns that I'll write about in the further messages:

[imaNNeo]

I think it's better to specifically mention that it is related to the text in it's name.
So I would go with textRotation (the same for textStyle)

[imaNNeo]

Also, padding is not what we have here. I think we can use offset name here.
And I would define a single property final Offset textOffset for both horizontal and vertical variables (dx and dy)

[imaNNeo]

And please don't forget to add the new properties in the lerp() function as well.
It helps us to have transition animation for these added properties!

[imaNNeo]

And my last comment:
Does it make sense to have a textAlignment property (which is Alignment) and defines the relative position of the text property inside the area?
I think at the moment we always draw on bottomLeft, but using this property we can make it customizable to allow people to draw it wherever they want. For example bottomCenter.