SVG-support

[haesleinhuepf]

We should add support for SVG files as discussed in this issue:

• [Programming question]: Drawing SVG files git-bob-playground#184

And demonstrated in the draw_vector_graphics function in this notebook:

• https://github.com/haesleinhuepf/git-bob-playground/blob/git-bob-mod-0hWbjlwr4m/svg_graphics_generator.ipynb

We should move the function draw_vector_graphics into _ai_github_utilities.py and call it within the function create_or_modify_file as new .svg alternative to .py, .ipynb, .pptx and .docx files. The function draw_vector_graphics should then return the content of the svg file instead of saving it.

git-bob implement this!