Add Fetchcode support for BItnami

[TG1999]

• No Standard Download Endpoint
  Bitnami does not expose a standardized or public API endpoint that maps a PURL (like pkg:bitnami/wordpress?distro=debian-12) to a downloadable artifact URL

• Dynamic and UI-Driven Distribution
  Bitnami primarily delivers packages via dynamic download pages (e.g., https://bitnami.com/stack/wordpress/installer) rather than static URLs or repository-like indexes. Files are often served behind redirect chains that involve JS or token validation.

• Lack of Versioned Index or Manifest
  There is no accessible versioned package index (like Packages.gz or repodata/primary.xml) to crawl or query for mapping names to URLs. This makes automation infeasible without scraping or reverse-engineering the frontend.

• Cloud-Native and VM-Image Focus
  Bitnami PURLs often refer to entire stacks or VM/container images, not raw binaries or .deb/.rpm packages. The “download” could refer to an OVA, Docker image, or even a marketplace listing—none of which follow a conventional artifact URL format.

• No Universal Host for Artifacts
  Bitnami-hosted downloads may come from AWS S3, Akamai, or Azure depending on the region and platform, with presigned URLs that expire. These cannot be deterministically generated or reused.