The OData stuff is missing things to generated a good OData api

[paule96]

Describe the bug

The metadata model for the odata endpoints only contains a single namespace. (your assembly namespace as name)
And this namespace don't include a EntityContainer.
For me for example it looks like that:

<?xml version="1.0" encoding="utf-8"?>
  <edmx:Edmx Version="4.0" xmlns:edmx="http://docs.oasis-open.org/odata/ns/edmx">
    <edmx:DataServices>
      <Schema Namespace="dynamicapi" xmlns="http://docs.oasis-open.org/odata/ns/edm">
        <EntityType Name="WeatherForecast">
          <Key>
            <PropertyRef Name="Id" />
          </Key>
          <Property Name="Date" Type="Edm.DateTimeOffset" Nullable="false" />
          <Property Name="TemperatureC" Type="Edm.Int32" Nullable="false" />
          <Property Name="Summary" Type="Edm.String" />
          <Property Name="Id" Type="Edm.Int32" Nullable="false" />
        </EntityType>
      </Schema>
      <Schema Namespace="Default" xmlns="http://docs.oasis-open.org/odata/ns/edm">
        <EntityContainer Name="Container" />
      </Schema>
    </edmx:DataServices>
  </edmx:Edmx>

The problem is that other software that tries to read the odata metadata model, will always say you API is empty. (for example Excel or PowerBi to call two by the name)

To fix this you must build your OData model with the following code:

Type model = // type of the model that should be added to your EDM model.
var method = typeof(ODataConventionModelBuilder).GetMethod("EntitySet");
method = method.MakeGenericMethod(model);
method.Invoke(odataBuilder, new object[] { model.Name });

after you run the above code for each modeltype you must run the following to publish the EdmModel:

var edmModel = odataBuilder.GetEdmModel();
services.AddSingleton<IEdmModel>(edmModel);

To Reproduce
Steps to reproduce the behavior:

1. Go to '/odata/$metadata'
2. Review the XML
3. It should look like that:

<?xml version="1.0" encoding="utf-8"?>
  <edmx:Edmx Version="4.0" xmlns:edmx="http://docs.oasis-open.org/odata/ns/edmx">
    <edmx:DataServices>
      <Schema Namespace="dynamicapi" xmlns="http://docs.oasis-open.org/odata/ns/edm">
        <EntityType Name="WeatherForecast">
          <Key>
            <PropertyRef Name="Id" />
          </Key>
          <Property Name="Date" Type="Edm.DateTimeOffset" Nullable="false" />
          <Property Name="TemperatureC" Type="Edm.Int32" Nullable="false" />
          <Property Name="Summary" Type="Edm.String" />
          <Property Name="Id" Type="Edm.Int32" Nullable="false" />
        </EntityType>
      </Schema>
      <Schema Namespace="Default" xmlns="http://docs.oasis-open.org/odata/ns/edm">
        <EntityContainer Name="Container">
             <EntitySet Name="WeatherForecast" EntityType="dynamicapi.WeatherForecast"/>
        </EntityContainer >
      </Schema>
    </edmx:DataServices>
  </edmx:Edmx>