Working on DecodePlateDialog class.

Improvements to scanning and decoding.
Resolves #1840: Specimen link instruction message change
Documentation updates
Documentation updates
Working on DecodePlateDialog class.

Improvements to scanning and decoding.
Continuing work on DecodePlateDialog class.

Decoding now working.
Using new decode image dialog.

- Scan link, assign and dispatch now use DecodeImageDialog.
- removed fake scan from specimen link
- removed fake scan from specimen link