Upgrade intermediate 2D and 3D meshes and add I/O component

[rmontuoro]

This PR features the following updates:

• Add the SWIO component to the NEMS coupling infrastructure

• Add plasma species, ion and electron temperature, and ExB components to the internal NUOPC Field Dictionary

• Upgrade methods to build intermediate 2D and 3D mesh objects internally and consistently with WAM, removing the need for an input file. The intermediate 3D mesh is now built using absolute heights (km)

• Introduce config file for the SWPC mediator, to read in vertical levels for the intermediate 3D mesh and output options for both the 2D and 3D mesh. The default file name (med.rc) can be replaced using the mediator's attribute ConfigFile in NEMS configuration file (nems.configure). More details are available on the linked Wiki section.

• Disable the hierarchy protocol by default to prevent NUOPC from adding unnecessary connectors, improving runtime performance

• Minor code improvements and cleanups

[rmontuoro]

This PR was posted to the wrong repository. Will create a new PR including the listed changes in the near future.