VRT: add a new mode to apply chained processing steps that apply to s… #4921

Job	Run time
build-windows-msys2-mingw	28m 19s
build-linux-ubuntu-focal	1h 4m 22s
build-mac	17m 59s
build-windows-conda	25m 36s
build-windows-conda-csharp-only	0s
build-windows-minimum	27m 19s
	2h 43m 35s

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