Implement visualisation for multiple sequence alignment

[sebschulz1]

Currently, we cannot visualise results from the tracy assemble process. So, we need a visualisation tool for assembled/overlapping DNA sequencing results.

Priority
Sabre seems to be the quickest option. The effort it takes needs to be discussed. Another point to discuss is what it would take to show genetic element annotations in Sabre as was done for Sage (#26).
In Sabre, Sanger sequencing electropherograms cannot be visualised. The user would have to refer to another visualisation tool like Indigo and/or Sage.

Other options and comments

• Pearl which however appears relatively complicated (Add Pearl visualisation #37). Thus, we put this on hold for now, also because Sabre provides some visual advantages for multiple sequence alignments.
• Integrated Genome Viewer (IGV) which was previously suggested. Here, it needs to be discussed what it would take to integrate it and if it does provide substantial advantages over Sabre. Sanger trace electropherograms cannot be visualised in IGV. One advantage could be that genetic element annotations can be visualised by uploading an annotation file (e.g. gtf). Sebastian to test IGV before implementation (handled in Test IGV for alignment visualisation #52).