Script GUI file upload

[will-moore]

Ported from ome/openmicroscopy#6096

See ome/openmicroscopy#6095

Currently, some scripts that require a File use the convention of a parameter named File_Annotation to allow the user to choose a previously created FileAnnotation ID.

This PR adds a File chooser input to parameter named File_Annotation which allows users to pick a local file from the Run-Script dialog in webclient. This will be used to create a File Annotation in OMERO and the ID will be passed to the File_Annotation script parameter.

To test:

• Choose a script that has a File_Annotation parameter, such as "Populate Metadata" (https://github.com/ome/scripts/blob/develop/omero/import_scripts/Populate_Metadata.py)
• The script dialog will allow you to choose a file:

• This will allow you to pick a local File to upload
• When the script is run, a new FileAnnotation is created in OMERO (not linked to anything) and the ID is passed to the File_Annotation script parameter (so the script should work as expected)

[pwalczysko]

This works as described in the header of this PR.

Ready to merge FMPOV