Consider persistent identifiers for pages in the app

[surchs]

I guess the goal would be to have persistent and unique identifiers for each page/view you can navigate to. Numeric identifiers are easy to make unique and persistent, but they are hard to read and debug. So maybe just a string identifier like column_annotation and multi_column_annotation and so on. Presumably such a list would have to live in the central store of the app.

Originally posted by @surchs in #37 (comment)

This came up in the context of using the label of a nav-button as a cypress selector - which seems brittle. But what should we use instead?