Introduces a basic CSV import module for bulk-importing account transactions.
Changes include:
- User can load a CSV
- User can configure the column mappings for a CSV
- Imported CSV shows invalid cells
- User can clean up their data directly in the UI
- User can see a preview of the import rows and confirm import
- Layout refactor + Import nav stepper
- System test stability improvements
* Initial foundational pass at multi-currency
* Default format currency
* More work on currency and exchanging
* Re-build currencies on change
* Currency import/setup
* Background job overhaul + cheaper OXR plan support
* Lint fixes
* Test fixes
* Multi-currency setup instructions
* Allow decimals in the balance field
* Spacing fix for form
---------
Signed-off-by: Josh Pigford <josh@joshpigford.com>