[BUG] Some text can't be translated due to fields out of translations

[crwilcox]

Some entries are hard to translate as text is built up with separate contexts.

From #981 :

Yes, they are numbers and dates and I can keep them. But there are some texts that are added outside the templates, such as (from https://github.com/nextstrain/auspice/blob/master/src/components/info/info.js#L91)

const prefix = branchLengthsToDisplay !== "divOnly" ? t("and comprising") : t("comprising");
const filterText = arrayToSentence(filterTextArr, {prefix: prefix, capatalise: false});
if (filterText.length) {
summary += ${filterText};
} else {
summary += ". ";
}
In this case, the code assumes that you can add filterText after the template and there's currently no way to control it.