2.5.24 Delay picture analysis through ActiveJob

Related to the audit.

The application should use the analyze_later method instead, so that the analysis task is enqueued in ActiveJob. Please note that this is the default ActiveStorage behaviour, so manual calls to analyze or analyze_later may not be required in the first place.

The logic was introduced to sanitize SVG inputs, and have the cleaned file directly available in the next request. We need to check if this flow can be improved, or maybe drop support for SVG files as maps background : we rely on an outdated version of SVGo with functionalities missing in the next version.