* ASCII85Decode
* ASCIIHexDecode
* RunLengthDecode

When you open a document as owner, you can now manipulate stream
filters via the context menu. The available options at the moment are
the following:

1. Remove all filters from a stream. I.e. save the decoded stream into
   the file.
2. Add an `ASCII85Decode` filter.
3. Add an `ASCIIHexDecode` filter.
4. Add a `BrotliDecode` filter with the default compression level.
5. Add a `FlateDecode` filter with the default compression level.
6. Add a `RunLengthDecode` filter.

When you add a filter, they are layered on top, not replaced. So you
could test some of the more unorthodox configurations.

Additionally, when you save a stream now, it is saved without any
filters applied by default. And now the `Length` value is correctly
updated on the stream.

Now you can change this in the preferences window. This will affect the
streams created automatically by iText itself and the default filter
used, when saving stream. You can still remove all filters afterward,
if required.

This seems less unexpected, than what was happening before. Still a bit
hacky though...