Initial implementation of 3D Print Demand plugin

Dashboard plugin for InvenTree showing aggregated demand for 3D printed
parts across open build and sales orders, with colour-coded deficit column.

setup.py

@@ -0,0 +1,17 @@
+from setuptools import setup, find_packages
+
+setup(
+    name='inventree-print-demand',
+    version='0.1.0',
+    description='InvenTree plugin to show aggregated 3D print demand across open orders',
+    author='Micromelon',
+    license='MIT',
+    packages=find_packages(),
+    include_package_data=True,
+    install_requires=['inventree'],
+    entry_points={
+        'inventree_plugins': [
+            'PrintDemandPlugin = inventree_print_demand.plugin:PrintDemandPlugin',
+        ],
+    },
+)