text: Title: Fail to run PhonemeCoverage.ipynb in Notebooks.
  Body: ### Describe the bug
  
  
  Thank you for sharing your code for phoneme coverage analysis using TTS. It has been very helpful. However, I have encountered some issues while trying to execute the notebook due to the lack of certain functions provided in the https://github.com/mozilla/TTS/ repository.
  
  To be specific, I have noticed the following problems:
  
  - The` load_config` function is not available in `TTS.utils.io`.
  - The `load_tts_samples `function is not available in `TTS.tts.datasets.formatters`.
  - The notebook requires a config file as input, but no example config files have been provided.
  - The `load_tts_samples` function requires a parameter `formatter` to be specified.
  - The `phoneme_to_sequence()` and `sequence_to_phoneme()` functions are not available in `TTS.tts.utils.text`.
  - It is necessary to specify the parameter `language` in `tokenize.text_to_ids()`.
  
  Although I was eventually able to resolve these issues, the process was quite cumbersome. It would be great if these issues could be addressed to make the notebook more user-friendly.
  
  ### To Reproduce
  
  ```
  cd ~/TTS/notebooks/
  jupyter notebook
  execute "phoneme coverage" notebook
  ```
  
  ### Expected behavior
  
  _No response_
  
  ### Logs
  
  _No response_
  
  ### Environment
  
  ```shell
  - TTS version 1.3.20
  ```
  
  
  ### Additional context
  
  _No response_