[materialx] Add port MaterialX 1.38.4#24614

Merged

BillyONeal merged 6 commits intomicrosoft:masterfrom theblackunknown:materialx

May 11, 2022

+80

Commits on May 9, 2022

Commits on May 10, 2022

Switch version-semver -> version
theblackunknown
committed

Commits on May 11, 2022