SME: editing multiple parameters at once doesn't save first parameter

Description

If you edit multiple parameters in the Spice Model Editor at once (i.e. open SME, edit a parameter, edit another parameter, then click OK) only the last parameter gets saved correctly to the Sim.Params field. The other fields get added with the default value, or sometimes don't get added, rather than being added with your selected value.

Steps to reproduce

1. Open attached schematic probe_mosfet_currents.zip
2. Edit V1 symbol properties
3. Click Simulation Model button
4. Click in "ac" parameter cell
5. type "1"
6. Click in "ph" parameter cell
7. type "1"
8. Click OK
9. examine Sim.Params field. It contains ac=0 ph=1, rather than ac=1 ph=1 as desired.

KiCad Version

Application: KiCad Schematic Editor arm64 on arm64

Version: (7.0.0-rc2-249-gc22fb390ec), release build

Libraries:
	wxWidgets 3.2.1
	FreeType 2.12.1
	HarfBuzz 5.3.1
	FontConfig 2.14.0

Platform: macOS Monterey Version 12.2.1 (Build 21D62), 64 bit, Little endian, wxMac

	wxWidgets: 3.2.1 (wchar_t,wx containers)
	Boost: 1.80.0
	OCC: 7.6.3
	Curl: 7.77.0
	ngspice: 38
	Compiler: Clang 13.0.0 with C++ ABI 1002

Build settings:
	KICAD_SPICE=ON