fix(microprints): pass unique id to source_viewer to fix DOM state

- source_viewer now receives id="source-viewer-#{path}" for unique DOM ids
- Fixes stale content bug when switching between expanded files

app/lib/firehose_web/live/microprints_live.ex

@@ -81,6 +81,7 @@ defmodule FirehoseWeb.MicroprintsLive do
                     content={source}
                     highlighted_line={@highlighted_line}
                     language="elixir"
+                    id={"source-viewer-" <> path}
                   />
                 <% end %>
               <% else %>