SDV 2.0: Update metadata auto-detection to the new V2 format

[npatki]

Problem Description

Starting from SDV 2.0, we will have an enhanced metadata that includes the ordinal sdtype as well as range information.

The metadata auto-detection should be updated to adhere to this format.

Expected behavior

Update the detect_from_dataframes and detect_from_dataframe functions to be compatible with SDV. This means the following changes:

1. The METADATA_SPEC_VERSION should be "V2"
2. There should no longer be a computer_representation field for numerical sdtypes
3. The ordinal sdtype should be detected. This is the sdtype we should give to low-cardinality columns that are represented as integers or whole numbers (could be floats like 1.0, 2.0, etc.). Currently these are marked as categorical.
4. The min_range, max_range, range_values, range_is_nullable, and decimal_places should be detected based on the training data.
   • When adding the list of values, we should only add them if there are <500 unique values; otherwise the JSON might get too long.

Additional context

No backwards compatibility is needed since this is for SDV 2.0.

Merge into a feature branch for SDV 2.0, as there will be other issues that are also needed for this version.