Refactor CircleCI workflows

[mathomp4]

Description

This PR refactors the CircleCI CI to be a bit more flexible. It partitions up the workflows in a more logical way so things can be targeted if needed.

Related Issue

Motivation and Context

Makes the CI more flexible.

How Has This Been Tested?

If the CI works, it works! Note: I'll need to fix up the GitHub branch requirements for this.

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)
• Trivial change (affects only documentation or cleanup)

Checklist:

• I have tested this change with a run of GEOSgcm (if non-trivial)
• I have added one of the required labels (0 diff, 0 diff trivial, 0 diff structural, non 0-diff)
• I have updated the CHANGELOG.md accordingly following the style of Keep a Changelog

[mathomp4]

Pinging @sshakoor1