Protein feature viewer: Amending modification coordinates

[ValWood]

          @ValWood I see, but those should be ammended at some point as well (I think). For now we have only fixed the ones in the HTP files, not the ones stored in Canto. We can discuss this on the next meeting, but I think it would be better to store them right in Canto and have them displayed differently on the "modification" section of the gene page, than keep storing the offsetted coordinates.

Originally posted by @manulera in pombase/website#2053 (comment)

[ValWood]

Original comment

i) we will need to deal with the histone special case for modifications, histones residues are always referred to (numbered) after the methionine has been removed in the mature form (check out hht1 lysine K14).
ii) special case 2 CTD domain residues in rpb1 and spt5 (will affect variants, but for rpb1 I see we also have
modified residue CTD_S5 removed by etc

[ValWood]

i) in the protein feature display the actual sequence coordinates will work, so nothing to do here.

ii) Display for CTD will be dealt with here pombase/website#2078