feat: Ability to specify what dots should be drawn

[herrrta]

• fixes Ability to specify what dots should be drawn #138

Example:

[ehsannarmani]

Hi @herrrta , thanks for contributing and adding this feature.
First, i think the confirmDraw name for that lambda is better than canDrawPoint
Second, i think having the dataIndex in that lambda would be usefull (imagine you have two lines, in the first line you want draw all of points, but in other lines, you want just draw first and last point, here it can be usefull)
Third, i think if default value would true, is better than nullable lambda:

val confirmDraw: (dataIndex:Int,valueIndex: Int, value: Double) -> Boolean = { true }

[herrrta]

All done

[ehsannarmani]

thanks