Issue description

Instead of using a PDF to generate the layout and link it to the segments an HTML could be used directly. 

Questions to clarify

1. What sources of HTML are supported?
2. How should resources externally to the HTML file be handled (what preconditions must be fullfilled, to make that work)?
3. Should it be possible to use more than one HTML file for a single task as layout file?

Initial Implementation:

• Only one HTML-file as review-source

• JS will be stripped for security-reasons

• HTML as VisuelReview source either as:
  • HTML-File + assets in the import zip
  • as HTML-file in the task-dialog
  • as URL in the task-dialog (will be fetched with wget)

• If HTML is the imported file format and visualReview folder is empty
  • Make it possible to directly use the first HTML in the import folder as layout for visualReview
  • Make this configurable via system configuration, if this should happen or not
• Multiple files in the import-zip: the first one (sorted by name) wins
• Processing of segments like with pdfToHtmlEX output
• No "Frame-Moving" in the review-HTML like with pdfToHtmlEX

Later Steps:

• Multiple Input files
• Switch to t5-specific tags in the segmentation insteaad of <span> and <div>