fix(Members): enforce currency for totalAmountDonatedFromTo

[Betree]

Fix opencollective/opencollective#8265

[seer-by-sentry]

Potential bug: The totalAmountDonatedFromTo loader now filters by currency, causing it to underreport totals for collectives that have changed their currency over time.

• Description: The totalAmountDonatedFromTo loader was modified to group and filter transactions by currency. However, call sites provide the collective's current currency. Since collectives can change their currency over time (e.g., when changing hosts), this new logic will exclude any historical transactions made in a different currency. For example, if a collective switches from EUR to USD, any prior donations made in EUR will be ignored when calculating the total, leading to underreported donation amounts. This affects financial reporting and the member donation totals displayed in the UI.

• Suggested fix: Modify the loader to sum all transactions between a donor and a collective, regardless of currency. This likely involves removing the currency field from the GROUP BY and WHERE clauses of the underlying query. The loader should aggregate totals across all currencies to provide a complete historical sum.
  _{severity: 0.75, confidence: 0.98}

_{Did we get this right? 👍 / 👎 to inform future reviews.}