[TTS] Replace IPA lambda arguments with locale string
# What does this PR do ?

Currently you cannot configure the IPATokenizer in .yaml config because there is no way to modify the lambda arguments. This PR replaces the lambda arguments with a locale string that maps to the correct behavior, which now just maps to English vs Non-English.

An alternative approach would be to replace the lambda arguments with a new class/interface, but we thought that was too complicated for now. And that having default configurations available that someone can control with just a language/locale string would be nice to have regardless.

**Collection**: [TTS]

# Changelog 
- Replace IPA tokenizer lambda arguments with locale string that maps to English vs non-English IPA functions.

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**Pre checks**:
- [x] Make sure you read and followed [Contributor guidelines](https://github.com/NVIDIA/NeMo/blob/main/CONTRIBUTING.md)
- [x] Did you write any new necessary tests?
- [ ] Did you add or update any necessary documentation?
- [ ] Does the PR affect components that are optional to install? (Ex: Numba, Pynini, Apex etc)
  - [ ] Reviewer: Does the PR have correct import guards for all optional libraries?
  
**PR Type**:
- [ ] New Feature
- [x] Bugfix
- [ ] Documentation