Fixes: U4-4353 You are able to create duplicate content/media/member type's with the same alias
fixes unit tests
Merge remote-tracking branch 'origin/6.2.0' into 7.1.0

Conflicts:
	src/Umbraco.Web.UI/umbraco/create/simple.ascx
	src/Umbraco.Web.UI/umbraco/developer/DataTypes/editDatatype.aspx
	src/Umbraco.Web/Umbraco.Web.csproj
	src/Umbraco.Web/umbraco.presentation/umbraco/create/nodeType.ascx.cs
	src/Umbraco.Web/umbraco.presentation/umbraco/developer/DataTypes/editDatatype.aspx.cs
	src/umbraco.cms/businesslogic/datatype/DataTypeDefinition.cs
Fixes merge issues