Make the get_parameters function consistent between synthesizers

[npatki]

Problem Description

Currently, almost all synthesizers have a method called get_parameters and there is some inconsistency between what is returned here. Let's align the return value of this function to the overall synthesizer representation.

Expected behavior

The parameters of a synthesizer are the optional input values during instantiation, excluding items such as the metadata, constraints, preprocessing, or individual table-level synthesizers.

1. For all synthesizers: The get_parameters call should include all optional settings during instantiation. They should include all of the optional settings.
   • If a user inputted them, include the user-inputted value
   • If a user did not input a setting, include the default value
2. Add the get_parameters call to the SingleTablePreset (with parameters 'name' and 'locales')
3. For multi-table synthesizer, only include the top-level parameters for the multi-table algorithm
   • Same a (1), include all settings during instantiation, even the default ones
   • Do not include the 'tables' dictionary. We will re-establish a different call to get these values.
4. Make an exception for the single table DayZSynthesizer: This synthesizer should continue to include the 'columns' dictionary with instructions for how to make each column -- including default values.

Additional Context

>>> synth = HSASynthesizer(metadata, locales=['en_US', 'en_GB'])
>>> synth.get_parameters()
{
  'locales': ['en_US', 'en_GB'],
  'default_num_clusters': 3 # default
}

>>> synth = DayZSynthesizer(metadata)
>>> synth.add_numerical_bounds(column_name='age', min_value=18, max_value=100)
>>> synth.get_parameters()
{
  'locales': ['en_US'] # default,
  'columns': {
    'age': {
      'min_value': 18,
      'max_value': 100
    }
  }
}