Error E_MISSING_CLDR with Globalize.currencyFormatter

### Issue: Error E_MISSING_CLDR with Globalize.currencyFormatter

#### Description
The `Globalize.currencyFormatter` function is throwing an `E_MISSING_CLDR` error when using `Globalize.formatCurrencyToParts` with certain currencies like BGN (Bulgarian Lev). This issue arises because the new CLDR version does not include symbols for currencies that traditionally do not have symbols.

#### Error Details
When calling `Globalize.formatCurrencyToParts(23.50, 'BGN');`, the error message is:
```
Error: E_MISSING_CLDR: Missing required CLDR content `main/en-US/numbers/currencies/BGN/symbol`.
```

#### Background
Previous versions of CLDR provided a default symbol for every currency, regardless of whether it had a symbol in practice. For example, BGN previously had 'BGN' as its symbol in the CLDR, but this is no longer the case in the newer versions.

#### Questions
- **Are you facing this issue as well?**
- **Is there any known workaround?**
- **Can we pass a default symbol when calling the function to mitigate this issue?**

#### Proposed Solution
Actually I am using this function in a function that is in used at 1000s of places so do not want to add the fix that can have bigger impact and can open testing

Globalize.js - Version 1.7.0
CLDR JavaScript Library v0.5.3 2020-08-05T21:43Z @rxaviers

Your insights and suggestions on this matter would be greatly appreciated.