Add variables to GFS_init_type

[laurenchilutti]

Description

This PR and PR NOAA-GFDL/atmos_drivers#24 address the following comment from the review of PR #22:

"The designed way to get this information to the physics from outside is to use the GFS_init_type. This type is populated with dycore and other external to the physics information within the atmos_model.F90::atmos_model_init function and it is passed to GFS_Initialize, where it is passed to the Model%init procedure."

Fixes # (issue)

How Has This Been Tested?

Checklist:

Please check all whether they apply or not

• My code follows the style guidelines of this project
• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• My changes generate no new warnings
• Any dependent changes have been merged and published in downstream modules

[lharris4]

Glad we could clean this up. Thanks for handling this.