XD-1884 Added type validation to SimpleModuleModuleOptionsMetadata

This adds some type validation for simple modules, i.e., those only backed by property descriptors.  Before, the following command would succeed. Now we get:

xd:>stream create test --definition "http --port=foo | log"
Command failed org.springframework.xd.rest.client.impl.SpringXDException: The value 'foo' is the wrong type for option 'port'. The required type is int.
ModuleOption only has default value, the user values are mapped in interpolate, unless I'm missing something.  I'm not sure what that code snippet is doing exactly...