Add TIFF output format support

Summary

Add support for TIFF as an output format.

Context

The COMPARISON.md feature comparison identifies this as a gap between JairoSVG and EchoSVG.

Implementation Notes

Similar to JPEG output, TIFF can be added via Java's ImageIO:

1. Create a TiffSurface class (similar to PngSurface)
2. Use ImageIO.write(image, "TIFF", outputStream) in the finish() method
3. Add toTiff() method to ConversionBuilder
4. Add tiff to the CLI format options

Note: TIFF support in ImageIO may require the javax.imageio TIFF plugin (included in JDK 9+). Since JairoSVG requires Java 25+, this is available by default.