[Feature]: Add `sql-datatype` to the SDK discovery and catalog.

[BuzzCutNorman]

Feature scope

Taps (catalog, state, stream maps, etc.)

Description

It would be very helpful if SDK based taps during the discovery process of a database grabbed column data types and placed them into the catalog metadata area for the column in the field of sql-datatype. The sql-datatype field is a reserved keyword mentioned in the singer discovery documentation.

https://github.com/singer-io/getting-started/blob/master/docs/DISCOVERY_MODE.md#metadata

Keyword	Tap Type	Discoverable?	Description
sql-datatype	database	discoverable	Represents the datatype of the database column

        {
          "breadcrumb": [
            "properties",
            "name"
          ],
          "metadata": {
            "sql-datatype": "varchar(255)",
            "selected-by-default": true
          }
        }

[stale]

This has been marked as stale because it is unassigned, and has not had recent activity. It will be closed after 21 days if no further activity occurs. If this should never go stale, please add the evergreen label, or request that it be added.

[edgarrmondragon]

Related: #1903

[stale]

This has been marked as stale because it is unassigned, and has not had recent activity. It will be closed after 21 days if no further activity occurs. If this should never go stale, please add the evergreen label, or request that it be added.

[edgarrmondragon]

Related: #1903