ISO Currency Changes 2025

[olliemath]

We need to add the following ISO4217 changes to the schemas (consult https://en.wikipedia.org/wiki/ISO_4217 for details):

• CUC (Cuban Convertible Peso) redenominated to CUP in 2021
• SLL (Siera Leoneon Leone) redenominated to SLE in 2022
• HRK (Croatian Kuna) replaced by EUR in 2023
• ZWL (Zimbabwean Dollar - 4th/5th) redenominated to ZWG in 2024
• ANG (Dutch Angolan Guilder) redenominated to XCG in 2025

Suggest doing it in two stages:

• Add new codes (CUP, SLE, ZWG, XCG) and notify of deprecated currencies (feat: add new iso4217 currencies #429)
• Remove CUC, SLL, HRK, ZWL, ANG at a later date (refactor: remove legacy iso currency codes #430)