In the transcript details panel, under the Sequence header, currently we have "CDS", "cDNA", and "genomic" as options. This will add "protein" to those options.

Basically this will be the same as getting the "CDS" sequence, but the sequence is translated to a protein sequence before being displayed. This can use the defaultCodonTable from @jbrowse/core/util, the same as is used in packages/jbrowse-plugin-apollo/src/LinearApolloDisplay/stateModel/rendering.ts.

There is already a color code for protein in packages/jbrowse-plugin-apollo/src/FeatureDetailsWidget/TranscriptSequence.tsx that isn't used yet, but we can change the color if it doesn't look right.