[TriangleAnnotator, DotAnnotator] - allow customization of the contour color #1403

[Kadermiyanyedi]

This PR introduces a new outline_color argument to the TriangleAnnotator and DotAnnotator classes, allowing users to customize the outline color when rendering annotations. Previously, while users could set outline_thickness to render an outline, the color was not configurable. With this enhancement, outline_color can now be set and will integrate seamlessly with the existing color_lookup system, accepting values of type Union[Color, ColorPalette].

Key Changes

• Added outline_color argument to TriangleAnnotator and DotAnnotator.
• Integrated outline_color with the existing color_lookup mechanism.

resolve https://github.com/roboflow/supervision/issues/1403

For testing purposes, please refer to the provided Colab link.

Please review thank you :)

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