* Enhance security handling logic:
- Prioritize user's country in sorting securities and country codes.
- Add comprehensive mapping for MIC codes to user-friendly exchange names.
- Revamp combobox to consistently pull from a provider when available.
- Improve handling of custom ticker and exchange input fields.
* Localize securities combobox display and exchange labels.
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Co-authored-by: luckyPipewrench <luckypipewrench@proton.me>