Transcript widget upates

[garrettjstevens]

I've added a new view on the AnnotationFeature model called transcriptParts. It returns the list of all parts of a transcript including UTRs, CDS locations, and introns. the cdsLocations view on the AnnotationFeature model is now a reference to transcriptParts with everything but CDS locations filtered out.

This has been used to replace a lot of cumbersome custom transcript-parsing logic in the TranscriptDetailsWidget to make it easier to maintain and in some cases more accurate. Here are some of the changes:

• "CDS and UTRs" section renamed to "Structure" (as in "Structural annotation")
• Transcript structure is now given in 5` to 3` order for both strands
• Extraneous entries in splice sites column removed
• CDSs now color-coded by frame to match track coloring
• New CDS frame color scheme based on the Okabe and Ito colorblind-friendly palette
  • Also gives reverse strand a unique color palette for easier identification
• Color coding of sequence is more efficient and has improved visibility
• "Copy sequence" action now copies HTML and plain text simultaneously, allowing "Paste" to keep colors and "Paste without formatting" to keep only text in applications like Google Docs.

Before

After