Feature Request: Show percentage gain excluding transactions

[kakulukia]

As this is the default for my stock broker, I was irritated at first looking at the chart in the BitBox app.

Would be cool to have a switch to not replace the current logic but let the user decide as both versions are helpful. BUT especially the ALL tab is currently probably only meaningful for somebody that started with a one time investment.

For my savings plan it currently shows over 3000% which feels like useless information at this point.

Feel free to point out why the app is showing it that way, but I currently don't get it. 🧐