class SeekableDecompressor

Decompresses data archive from buffer, `compressed_buf`, which has size `max_compressed_size`,

starting at _uncompressed_ byte offset, `offset`. Decompress at most `uncompressed_size` bytes.

The actual archive contents is at most `max_compressed_size`, but may be smaller. Decompressed

data is written to `uncompressed_buf`, which has a size of `*uncompressed_size`. If the return

value is `ZX_OK, then the number of bytes written is written to `uncompressed_buf` is stored in

`*uncompressed_size`.

Looks up the range [offset, offset+len) in the decompressed space, and returns a mapping which

describes the range of bytes to decompress which will contain the target range.

`max_len` is the maximum length the returned decompressed range will span, and

must be greater than zero.

The concrete implementation is free to return an arbitrarily large range of bytes as long as it

is less than or equal to `max_len`. The returned decompressed range is guaranteed

to contain `offset` but its length might be less than `len` if it was trimmed to a smaller

`max_len`.

The implementation should also ensure that the compressed data does not exceed

`max_len`, and callers may rely on this. One would hope that this is normally the

case (since that is the point of compression), but it's technically possible for compressed

data to take up more space than its uncompressed form.

Returns the CompressionAlgorithm that this SeekableDecompressor supports.