Update Language/Script/Region Subtags

Updated 2021-02-17 by Yoshito Umaoka

This updates language codes, script codes, and territory codes.

  TestLstrConsistency {
  Error: (TestValidity.java:542) Missing aliases for supplementalMetadata: 2
   <languageAlias type="mrd" replacement="mgp" reason="deprecated"/> <!-- Western Magar ⇒ Magar -->
   <languageAlias type="shl" replacement="mrh" reason="deprecated"/> <!-- Shendu ⇒ Mara -->
- re-run ConvertLanguageData and GenerateLikelySubtags after that (?)