Substrait query plan validator

This crate implements a validator for Substrait query plans.

[dependencies]
substrait-validator = "0.1.4"

YAML file resolution

One of the complexities of validating Substrait plans is resolving the YAML extension files. By default, the crate only supports file://... URLs, but often, the YAML files will be stored remotely. To make handling this easier, you can enable curl as an optional dependency:

[dependencies]
substrait-validator = { version = "0.1.4", features = ["curl"] }

This adds the substrait_validator::Config::add_curl_yaml_uri_resolver() method, which will use libcurl to resolve the files, thus supporting all the common protocols (http, https, ftp, etc.). The downside is that the curl crate depends on system libraries.