Create 'Export project for sharing' command

[petebankhead]

Feature request

Is your feature request related to a problem? Please describe.
QuPath is commonly used for annotation, and the annotations need to be shared with others.

My approach is generally to zip up a project folder. The trouble with this is that it's necessary to then:

• Send the zipped project
• Send the original images
• Unzip the project
• Open the unzipped project in QuPath
• Match the URIs to the new image locations

Describe the solution you'd like
It would be nice to have a command to Export project for sharing that can do the zipping itself.

This could include options:

• Include thumbnails
  • Since thumbnails can be regenerated automatically by QuPath, removing them can reduce the zipped file size
• Include original images
  • This would involve copying the image files directly into a subdirectory of the project, and updating the URIs to make the project fully self-contained

Describe alternatives you've considered
The main alternative is to stick with the current method: document the zipping/unzipping process, but don't add anything to QuPath to help.

Additional context
Some considerations:

• If there are many images, or they are huge, then including them in the zip file might become problematic
• We need to take care with zipping/unzipping (e.g. ensuring we don't allow names with .. for security reasons, or use an established and secure library implementation)
• This approach only really works with the current, filesystem-based project approach. Any command might not be relevant if projects are stored some other way.