Trade imports should accept a currency, exchange, and ticker field

[zachgoll]

Discussed in https://github.com/maybe-finance/maybe/discussions/1656

^{Originally posted by jelloc January 23, 2025}

Describe the feature

When importing a CSV file of investment activities (buying/selling shares), you can tie a collumn to the Ticker field. When importing a CSV file of share transactions you should be able to set the following fields:

• Ticker (e.g. AMZN, AIR, HPE)
• Exchange (e.g. NYSE, ASX)
• Currency (e.g. NZD, AUD, USD)

Why is this feature important?

Ticker symbols aren't unique across all exchanges - for example, ANZ (Australia and New Zealand Banking Group Limited) uses the same ANZ ticker code on both the NZSE and ASX exchanges, but both are different shares with their own pricing and currencies.

If you import in the current state, it can't match the stock correctly so the activity and holdings may not be updated correctly. Manually adding all transactions as a workaround will work but is time consuming.

Additional context, screenshots, and relevant links