[SL-2426] [Feature] Add 'data_type' key to dimension spec

[Jstein77]

Is this your first time submitting a feature request?

• [X] I have read the expectations for open source contributors
• [X] I have searched the existing issues, and I could not find an existing issue for this feature
• [X] I am requesting a straightforward extension of existing metricflow functionality, rather than a Big Idea better suited to a discussion

Describe the feature

We should have a way to encode the data type of a column. We would update the dimension spec as follows:

dimensions:
 - name: [Required]
   type: [Required]
   data_type: [Optional] #the data type of the underlying column

This optional piece of metadata is useful in a few ways. It allows us to handle timezones and time type dimensions more easily, and can be used by integration partners to improve the user experience i.e using a boolean type filter instead of a string.

Describe alternatives you've considered

You could use the meta tag for this.

Who will this benefit?

No response

Are you interested in contributing this feature?

No response

Anything else?

No response

_SL-2426