[FEATURE] Currency convert when switched in app

**Is your feature request related to a problem? Please describe.** I'm always frustrated when I switch currencies and it doesn't convert from the displayed to the new currency selected. **Describe the solution you'd like** Set a base currency for a trip. If different currencies are selected after that it should convert to make it easier to plan and see prices. **Describe alternatives you've considered** I've considered putting everything in one currency but unfortunately the place I'm traveling to uses a different currency. i.e. I am traveling from Japan to the Philippines and trying to figure out food prices and local stays but they are both in local currency so I have to convert those into my local currency to place it in the app. **Additional context** Add any other context or screenshots about the feature request here.