Add roundmultiple function #133

Job	Run time
XML validation	16s
MSIS code validation (ubuntu-latest)	6s
MSIS code validation (macos-latest)	9s
C/C++ build (MSVC) (ON)	6m 25s
C/C++ build (Linux) (ubuntu-22.04, ON, ON, OFF, ON)	3m 37s
C/C++ build (MSVC) (OFF)	5m 16s
C/C++ build (MacOSX) (macos-12, 3.8)	4m 20s
C/C++ build (Linux) (ubuntu-22.04, ON, OFF, OFF, ON)	3m 49s
C/C++ build (MacOSX) (macos-14, 3.10)	2m 15s
C/C++ build (MinGW) (ON)	2m 33s
C/C++ build (Linux) (ubuntu-22.04, OFF, ON, OFF, ON)	3m 48s
C/C++ build (Linux) (ubuntu-22.04, OFF, OFF, OFF, ON)	3m 49s
C/C++ build (MinGW) (OFF)	3m 16s
C/C++ build (Linux) (ubuntu-20.04, OFF, OFF, ON, OFF)	5m 20s
Build Python Module from Source	0s
Code coverage	1m 49s
Matlab S-Function (macos-12)	6m 12s
Matlab S-Function (ubuntu-22.04)	14m 6s
Build Python wheels	0s
Matlab S-Function (windows-latest)	10m 12s
Build Windows installer	0s
Deploy Rolling Release	0s
Deploy Stable Release	0s
Deploy Documentation	0s
	1h 17m 18s

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