Split out common AD file plugin logic into core writer class, create ADTiffWriter

[jwlodek]

This now seems to mostly work, at least from the collection side. The data cannot be read back via tiled at the moment, however, so for now marking as draft, since I may need to edit the docs generated somewhat to account for this.

Addresses #595 .

TODO:

• Add tests for tiff writer
• Make sure we can read the data back through tiled
• Make sure HDF writer still works as it did.

[jwlodek]

@genematx Here are the ophyd async changes that introduce tiff writer support, specifically you can look at collect_stream_docs in the ADWriter class to see what I am emitting