Change ApiContext values to access different master catalogs in the same tenant.

Get_Product_From_Another_Master_Catalog.cs

[TestMethod]
public void Get_Product_From_Another_Master_Catalog()
{
    _apiContext.SiteId = null;

    _apiContext.MasterCatalogId = 2;
    var productResourceMC2 = new Mozu.Api.Resources.Commerce.Catalog.Admin.ProductResource(_apiContext);
    var productInMC2 = productResourceMC2.GetProductAsync("MAND-ARM-001").Result;

    _apiContext.MasterCatalogId = 1;
    var productResourceMC1 = new Mozu.Api.Resources.Commerce.Catalog.Admin.ProductResource(_apiContext);
    var productInMC1 = productResourceMC1.GetProductAsync("MAND-ARM-001").Result;

}