Out of line annotations can't target enum member

[mikepizzo]

Validating a schema that has out-of-line annotations targeting an enum member fails.

Assemblies affected

OData .Net lib 7.6-beta.

Reproduce steps

load and validate the following schema:

<edmx:Edmx Version="4.0" xmlns:edmx="http://docs.oasis-open.org/odata/ns/edmx">
  <edmx:Reference Uri="https://oasis-tcs.github.io/odata-vocabularies/vocabularies/Core.xml">
    <edmx:Include Namespace="Org.OData.Core.V1" Alias="Core"/>
  </edmx:Reference>
  <edmx:DataServices>
    <Schema Namespace="my.ns" Alias="myns" xmlns="http://docs.oasis-open.org/odata/ns/edm">
      <EnumType Name="MyEnum">
        <Member Name="MyMember" Value="0"/>
      </EnumType>
      <Annotations Target="myns.MyEnum/MyMember">
        <Annotation Term="Core.Description" String="This is an annotation"/>
      </Annotations>
    </Schema>
  </edmx:DataServices>
</edmx:Edmx>

Expected result

Successful validation

Actual result

Error: The property "MyMember" could not be found. Location (12, 10)

Additional detail

odata.net/src/Microsoft.OData.Edm/Csdl/Semantics/CsdlSemanticsVocabularyAnnotation.cs

Line 198 in ba32541

IEdmStructuredType type = this.schema.FindType(targetSegments[0]) as IEdmStructuredType;

doesn't handle enumType