dezoomify-rs: download ældre versioner

New supported image formats
dezoomify-rs can now open images directly from more museum, library, archive, and map viewers:
- XLimage image servers (*.imgf / *.imgi metadata URLs)
- Picturae Memorix (TopViewer) metadata, thumbnail URLs, and media API URLs
- Neptune Labs FSI Server images, including pages that embed an FSI server
- LizardTech ImageServer, Visual Library Server, and Hungaricana image services
- Web Map Tile Service (WMTS) capabilities documents, cached ArcGIS MapServer imagery, and basemapUrl viewer links
- pnav crop-based image services

Removals
- The NYPL dezoomer has been removed: NYPL no longer serves tile metadata, so it could never succeed.
- Special cases for pages that no longer exist or that no live site uses were removed: KBR multi-page XLimage viewers, three dead Zoomify sites (biblio.unibe.ch, bspe-p-pub.paris.fr, artandarchitecture.org.uk), the Fluid Engage XMLBroker, Flash-era zoomifyImagePath embeds, iframe following, and a few smaller unreachable variants. These had only ever been exercised by synthetic test fixtures.
Every URL pattern that remains is covered by a live test against a current website, so discovery no longer carries unreachable code.

Improvements
- Automatic discovery now follows redirects, viewer pages, and related metadata instead of requiring a direct tile URL.
- IIIF URLs with proxies, query parameters, and nested image paths now produce usable tile URLs.
- Images from the new formats get readable names derived from page titles and metadata.
- Tile cache entries now distinguish client headers and decryption, avoiding wrong-cache hits.
- Failed downloads no longer leave misleading output files behind.

This release reorganizes the code behind dezoomify-rs without changing the basic way you use the command-line tool.
The practical changes are:
- Zoom levels are listed consistently from smallest to largest, with clearer labels and more accurate dimensions.
- Discovered image titles are kept when files are saved, so output names are less likely to fall back to generic names.
- Custom request headers now take precedence as expected, and connection timeouts are applied correctly.
- The retired PFF servlet format was removed because it no longer has a verifiable live deployment.
The release includes updated Linux, macOS, and Windows downloads. No new image format was added in this release.