feat: add report export capabilities with Pandoc and WeasyPrint support

- Updated Dockerfiles to include Pandoc and WeasyPrint runtime libraries for report generation.
- Enhanced report retrieval functionality to include version siblings in the response.
- Modified report export process to utilize WeasyPrint for PDF generation, improving output quality.

surfsense_backend/Dockerfile

@@ -20,6 +20,10 @@ RUN apt-get update && apt-get install -y --no-install-recommends \
     libxrender1 \
     dos2unix \
     git \
+    pandoc \
+    libpango-1.0-0 \
+    libpangoft2-1.0-0 \
+    libharfbuzz-subset0 \
     && rm -rf /var/lib/apt/lists/*
 
 # Update certificates and install SSL tools