[TTS] relax hardcoded prefix for phonemes and tones and infer phoneme set through dict
# What does this PR do ?

1. previously, '#' was hardcoded as a prefix for Chinese phonemes and tones in both g2p and tokenizer. It is apt to raise errors if mismatched prefix symbols are applied for g2p and tokenizer.

2. previously, phoneme set and tone set are hardcoded as well. It would raise errors when the input phoneme dict contains different set of phonemes. Fixed this by inferring phoneme set based on input dictionary.

3. run pytest nightly and old NGC model checkpoint passed.
```
$ pytest --nightly tests/collections/tts/models/test_fastpitch.py::test_inference[tts_zh_fastpitch_sfspeech]

tests/collections/tts/models/test_fastpitch.py::test_inference[tts_zh_fastpitch_sfspeech] PASSED
```


**Collection**: [Note which collection this PR will affect]

# Changelog 
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