Validation fails on nested references in schema

This was discovered by using PowerShell 7 (It worked in Powershell 6) which uses this library.

The following test will fail (if put in SchemaTests.cs), because there are nested levels of $ref.

The test will be green if the definition of bar is changed from ""$ref"": ""#/myDefs/barType"" to ""type"": ""string""

I can submit a PR, if I get a little hint about where these references are resolved. (or even just submit this test as an PR)

        [Fact]
        public async Task When_property_name_is_double_ref_then_validation_works()
        {
            //// Arrange
            var jsonSchema = @"
    {
        ""$schema"": ""http://json-schema.org/draft-07/schema#"",
        ""myDefs"": {
            ""barType"": { ""type"": ""string"" },
            ""fooType"": {
                ""type"": ""object"",
                ""properties"": {
                    ""bar"": { ""$ref"": ""#/myDefs/barType"" }
                }
            }
        },
        ""type"": ""object"",
        ""properties"": {
            ""foo"": { ""$ref"": ""#/myDefs/fooType"" }
        }
    }";

            var jsonContent = @"
{
    ""foo"": {
        ""bar"": ""Something""
    }
}";

            //// Act
            var validator = new JsonSchemaValidator();
            var schema = await JsonSchema.FromJsonAsync(jsonSchema);
            var result = validator.Validate(jsonContent, schema);

            //// Assert
            Assert.Empty(result);
        }

Failure message:

Result StackTrace:	
at NJsonSchema.JsonSchema.GetActualSchema(IList`1 checkedSchemas) in C:\NJsonSchema\src\NJsonSchema\JsonSchema.Reference.cs:line 100
   at NJsonSchema.JsonSchema.get_ActualSchema() in C:\NJsonSchema\src\NJsonSchema\JsonSchema.Reference.cs:line 23
   at NJsonSchema.Validation.JsonSchemaValidator.ValidateProperties(JToken token, JsonSchema schema, String propertyName, String propertyPath, List`1 errors) in C:\NJsonSchema\src\NJsonSchema\Validation\JsonSchemaValidator.cs:line 360
   at NJsonSchema.Validation.JsonSchemaValidator.Validate(JToken token, JsonSchema schema, String propertyName, String propertyPath) in C:\NJsonSchema\src\NJsonSchema\Validation\JsonSchemaValidator.cs:line 92
   at NJsonSchema.Validation.JsonSchemaValidator.ValidateProperties(JToken token, JsonSchema schema, String propertyName, String propertyPath, List`1 errors) in C:\NJsonSchema\src\NJsonSchema\Validation\JsonSchemaValidator.cs:line 360
   at NJsonSchema.Validation.JsonSchemaValidator.Validate(JToken token, JsonSchema schema, String propertyName, String propertyPath) in C:\NJsonSchema\src\NJsonSchema\Validation\JsonSchemaValidator.cs:line 92
   at NJsonSchema.Validation.JsonSchemaValidator.Validate(JToken token, JsonSchema schema) in C:\NJsonSchema\src\NJsonSchema\Validation\JsonSchemaValidator.cs:line 73
   at NJsonSchema.Validation.JsonSchemaValidator.Validate(String jsonData, JsonSchema schema) in C:\NJsonSchema\src\NJsonSchema\Validation\JsonSchemaValidator.cs:line 63
   at NJsonSchema.Tests.Validation.SchemaTests.When_property_name_is_double_ref_then_validation_works() in C:\NJsonSchema\src\NJsonSchema.Tests\Validation\SchemaTests.cs:line 492

Result Message:	System.InvalidOperationException : The schema reference path '#/myDefs/barType' has not been resolved.