0.26.0

• BREAKING CHANGE: The lookup and lookup_prefix methods now return
  Ok(None) or Ok((None, prefix_len)) respectively when an IP address is
  valid but not found in the database (or has no associated data record),
  instead of returning an Err(MaxMindDbError::AddressNotFoundError).
  Code previously matching on AddressNotFoundError must be updated to
  handle the Ok(None) / Ok((None, prefix_len)) variants.
• BREAKING CHANGE: The MaxMindDBError enum has been renamed
  MaxMindDbError and variants have been renamed and refactored. For
  example, IoError is now Io, InvalidDatabaseError is now
  InvalidDatabase, DecodingError is now Decoding,
  InvalidNetworkError is now InvalidNetwork. The MapError variant has
  been replaced by Mmap (under the mmap feature flag). Code explicitly
  matching on the old variant names must be updated.
• BREAKING CHANGE: MaxMindDbError no longer implements PartialEq.
  This is because underlying error types like std::io::Error (now
  wrapped by the Io and Mmap variants) do not implement PartialEq.
  Code comparing errors directly using == or assert_eq! must be
  updated, typically by using matches! or by matching on the error
  kind and potentially its contents.
• Refactored MaxMindDbError handling using the thiserror crate.
  Variants like Io, Mmap, and InvalidNetwork now directly wrap
  the underlying error types (std::io::Error, ipnetwork::IpNetworkError).
• Errors wrapping underlying types (Io, Mmap, InvalidNetwork) now
  correctly implement std::error::Error::source(), allowing inspection
  of the original cause.
• The Display implementation for MaxMindDbError has been refined to
  generally show only the specific error details, often including the
  message from the source error, rather than prefixing with the variant
  name.
• lookup_prefix now returns the prefix length of the entry even when the
  value is not found.
• Fixed an internal bounds checking error when resolving data pointers.
  The previous logic could cause a panic on a corrupt database.