AGS should throw validation error instead of exception for gradient outside of range

[softwareengineerprogrammer]

Example input:

# Example 1 from "Tabulated Database of Closed-Loop Geothermal Systems Performance for Cloud-Based Technical and
#    Economic Modeling of Heat Production and Electricity Generation"
# Koenraad Beckers Yaroslav Vasyliv Gabriela A. Bran-Anleu Mario Martinez Chad Augustine and Mark White
# Presented at the 48th Stanford Geothermal Workshop Stanford California February 6-8 2023
# This configuration is water filled U-loop with 1 lateral for direct-use heat
Is AGS, True
Closed-loop Configuration, 2, -- --Coaxial
End-Use Option, 2, -- ---direct heat
Number of Production Wells, 1, -- -- 1 production well accounts for the full configuration - 1 up, one down, and a horizontal section
Number of Injection Wells, 0, -- -- No injectors in a closed uloop
All-in Vertical Drilling Costs, 1000.0
All-in Nonvertical Drilling Costs, 1000.0
Exploration Capital Cost, 0
Production Flow Rate per Well, 20, -- -- kg/s for water / 40 kg/s for sCO2
Cylindrical Reservoir Input Depth, 3.0, -- ---kilometers
Gradient 1, 25.0, -- --deg.c/km
Nonvertical Length per Multilateral Section, 9000, -- --- m
Production Well Diameter, 8.5, -- - [inch]
Reservoir Depth, 3.0, -- ---kilometers
Injection Temperature, 60.0, -- ---deg.C
Plant Lifetime, 40, -- - years
Ambient Temperature, 20, -- --Deg.C "Dead-state temperature"
Electricity Rate, 0.10, -- --USD/kWh
Circulation Pump Efficiency, 0.8, -- ---[-]
#same as default Reservoir Thermal Conductivity, -- 3,     ---- W/m-K
#same as default Drilling Cost per Meter of Measured Depth, -- 1000,     ----$/m
#same as default Operation & Maintenance Cost of Surface Plant, -- 1.5,     -----%
#same as default Capital Cost for Surface Plant for Direct-use System, -- 100.00,    ----$/kWth
#same as default Dead-state Pressure, -- 1e5,     ---- bar
# *** Economic/Financial Parameters ***
# *************************************
Economic Model, 4, -- - Should be 1 (FCR model) 2 (Standard LCOE/LCOH model) 3 (Bicycle model) 4 CLGS.
Fraction of Investment in Bonds, 0.65, -- - [-] Required if Bicycle model is selected. See manual for details.
Inflated Bond Interest Rate, 0.07, -- - [-] Required if Bicycle model is selected. See manual for details.
Inflated Equity Interest Rate, 0.12, -- - [-] Required if Bicycle model is selected. See manual for details.
Inflation Rate, 0.025, -- - [-] Required if Bicycle model is selected. See manual for details.
Combined Income Tax Rate, 0.392, -- - [-] Required if Bicycle model is selected. See manual for details.
Gross Revenue Tax Rate, 0, -- - [-] Required if Bicycle model is selected. See manual for details.
Reservoir Stimulation Capital Cost, 0, -- - [M$/injection well] Reservoir stimulation capital cost per injection well
# *** Simulation Parameters ***
Print Output to Console, 1, -- - [-] Should be 0 (don't print results to console) or 1 (print results to console)