Fix svg exporting

[maxschommer]

Adding a draft PR to fix SVG exporting.

• Changed function generate_svg to write to a file or multiple files
• Added test cases for generate_svg which checks for exported SVG files
• Changed some print functions to logging calls to not clutter the stdout when generating SVG files

The main issue with generate_svg seemed to be that it never attempted to write to a file as documented. The user was also given no indications that it failed to generate any output.

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[maxschommer]

@googlebot I signed it!