code improvements

[frhl]

• [x] dataset is overwritten entirely when stratifying into interactors and non-interactors and the old dataset name can only be found using the suffix '(enriched)'. This should not be the case. Make new column that the rest of genoppi will look for. maybe col.id?
• [x] plot_overlay merges overlay data and regular data to find overlap. This messes up row structure. find a way to conserve this?
• [x] make_interactive is unstructured and is built on environements that are sent to add_genoppi_trace.R. Add internal tag or fix this structure.
• [x] add_trace_genoppi currently only handles legend_order through assigning the key to a factor. This is problematic when plot_overlay merges the data. Find a better way to do this the future.