Add textproc/p5-JSON-Validator

JSON::Validator validates a data structure against a schema. It can
load schemas from JSON, YAML, and perl data structures, and includes a
powerful schema-building DSL.

JSON is processed by Mojo::JSON (which will use p5-Cpanel-JSON-XS
if it's installed). YAML uses p5-YAML-LibYAML (YAML::XS).

WWW: https://metacpan.org/pod/JSON::Validator