Add verbosity to metadata auto-detection

[npatki]

Problem Description

When auto-detecting metadata, the algorithm makes many nuanced decisions about the columns, sdtypes, and other properties. Right now, it is not possible to easily view properties such as datetime or regex formats. The visualize function doesn't display this information; the only other alternative is to print out the JSON object, which is hard to parse.

Expected behavior

For all the metadata detection functions (multi-table detect_from_dataframes and single-table detect_from_dataframe), add a parameter called verbose:

• (default) False: Do not print out any information about what is detected
• True: Print out information about what is detected

If set to True, the metadata auto-detection should print out what it's doing. For example:

metadata = Metadata.detect_from_dataframes(data, verbose=True)

Detecting table 'hotels':
- Column 'hotel_id': sdtype='id', regex_format='HID_[0-9]{3}'
- Column 'city': sdtype='categorical'
- Column 'rating': sdtype='numerical', computer_representation='Float'

Detecting table 'guests':
- ...

Detecting primary keys:
- Table 'hotels': primary_key='hotel_id'
- Table 'guests': primary_key=None

Detecting foreign keys:
- Column 'guests.hotel_id' refers to column 'hotels.hotel_id' (updating sdtype to 'id')
- ...

Additional context

• Depending on the parameters, not all sections may be present
• Some of the sdtypes may change based on the foreign key detection (as the foreign key and primary key's sdtype should match)

[gsheni]

@npatki One thing I wanted to note, it seems the expected detection behavior in this issue is that PKs for tables are all detected at the same time.
However, we actually detect PKs table by table immediately after detecting the sdtypes in the table.

As a result, the verbose output would look as such:

Detecting table 'hotels':
- Column 'hotel_id': sdtype='id', regex_format='HID_[0-9]{3}'
- Column 'city': sdtype='categorical'
- Column 'rating': sdtype='numerical', computer_representation='Float'

Detecting primary key for table 'hotels':
- primary_key='hotel_id'

Detecting table 'guests':
- ...

Detecting primary key for table 'guests':
- No primary key found

Detecting foreign keys:
- Column 'guests.hotel_id' refers to column 'hotels.hotel_id' (updating sdtype to 'id')