validator: introduce experimental node:validator module #5881

Job	Run time
Build slim tarball	2m 25s
x86_64-darwin: with shared libraries	38m 46s
x86_64-linux: with shared libraries	27m 58s
aarch64-linux: with shared libraries	22m 29s
aarch64-darwin: with shared libraries	19m 37s
	1h 51m 15s

Provide feedback