Treat accessions and urls as special node traits

The schema defines these as "special" property, and we use them to render the value and link to be rendered via `<AccessionAndUrl>` within the tip-clicked panel.

These should not be available as valid traits for general display.

src/components/tree/infoPanels/click.js

@@ -218,7 +218,7 @@ const SampleDate = ({node, t}) => {
 const getTraitsToDisplay = (node) => {
   // TODO -- this should be centralised somewhere
   if (!node.node_attrs) return [];
-  const ignore = ["author", "div", "num_date", "gisaid_epi_isl", "genbank_accession"];
+  const ignore = ["author", "div", "num_date", "gisaid_epi_isl", "genbank_accession", "accession", "url"];
   return Object.keys(node.node_attrs).filter((k) => !ignore.includes(k));
 };