[Audit] SolarGridComp: pre-migration audit

## Component

**Name:** SolarGridComp
**Primary file:** `GEOSagcm_GridComp/GEOSphysics_GridComp/@GEOSradiation_GridComp/GEOSsolar_GridComp/GEOS_SolarGridComp.F90`
**Sub-repo:** GEOSradiation_GridComp
**Effort:** XL
**MAPL depth:** leaf

## Current state

- `VERIFY_(` calls: 10
- LOC: 8245

## Notes

_None._

## Links

- Parent epic: GEOS-ESM/GEOSgcm_GridComp#1241