refactor(enginemaster): Replace `pMaster` member names with `pMain` #1753

Job	Run time
Ubuntu 22.04 (gcc)	52m 59s
Ubuntu 22.04 (Qt 6.2, gcc)	46m 13s
macOS 11 x64	49m 5s
macOS 11 arm64	10m 51s
Windows 2019 (MSVC)	1h 19m 14s
Update manifest file on download server	40s
	3h 59m 2s

Provide feedback