Feature: SVG optimization

[petri-lipponen-movesense]

• Optimized svg image rendering by avoiding deepcopy (uses copy=False flag when calling add_item in svg.build_group where item is known to be not re-used). This reduces time to render SVG's by 50%-70%.

Checklist:

• A unit test is covering the code added / modified by this PR. N/A

• This PR is ready to be merged

• In case of a new feature, docstrings have been added, with also some documentation in the docs/ folder N/A

• A mention of the change is present in CHANGELOG.md

By submitting this pull request, I confirm that my contribution is made under the terms of the GNU LGPL 3.0 license.

[petri-lipponen-movesense]

I'm sure there are other parts of the SVG handling that can help, but this seemed to be the low hanging fruit. In my case it dropped ~100 page PDF generation from 27 minutes to 13...

[Lucas-C]

@allcontributors please add @petri-lipponen-movesense for code

[allcontributors]

@Lucas-C

I've put up a pull request to add @petri-lipponen-movesense! 🎉

[Lucas-C]

Wow, thank you very much @petri-lipponen-movesense! 👍

Excellent job, thank you very much for this contribution ❤️

[Lucas-C]

This has been released in https://github.com/py-pdf/fpdf2/releases/tag/2.8.3