Add support for ColumnDataTypes.Date (date-only) when creating columns

[areed1192]

Summary:
Currently, only columns of type ColumnDataTypes.Datetime (with time component) can be created. Add support for creating columns using a new ColumnDataTypes.Date value, enabling users to define and serialize date-only columns (without time information) in tables and datasets.

Relevant code references:

• ColumnDataTypes enum definition
• Column class and data_type handling
• Examples of column creation in samples/use_utils.py and samples/use_push_datasets.py

Acceptance Criteria:

• Users can define a new column with ColumnDataTypes.Date (date only)
• The API and logic accept, process, and serialize date-only columns correctly
• Update enum, column creation, documentation, and unit tests as needed

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Parent: #7

Assignee: @areed1192