Enclose return from DbDataReader handlers into a class

[Aniruddh25]

Not necessarily this PR, but perhaps this return type can be converted into a class so that this is easier to read. i.e.
class RowResult

• Dictionary<string, object?> Columns
• Dictionary<string, object> Properties

Originally posted by @seantleonard in #799 (comment)

[ayush3797]

Need to see if this is still an issue.

[ayush3797]

Looks like it is still an issue.