Feature: Supplier part pack size (#3644)

* Adds 'pack_size' field to SupplierPart model

* Edit pack_size for SupplierPart via API

* Display pack size in supplier part page template

* Improve table ordering for SupplierPart table

* Fix for API filtering

- Need to use custom filter class

* Adds functionality to duplicate an existing SupplierPart

* Bump API version number

* Display annotation of pack size in purchase order line item table

* Display additional information in part purchase order table

* Add UOM to purchase order table

* Improve receive items functionality

* Indicate quantity which will be received in modal form

* Update the received quantity as the user changes the value

* Take  the pack_size into account when receiving line items

* Take supplierpart pack size into account when receiving line items

* Add "pack size" column to purchase order line item table

* Tweak supplier part table

* Update 'on_order' queryset annotation to take pack_size into account

- May god have mercy on my soul

* Adds a unit test to validate that the on_order queryset annotation is working as expected

* Update Part.on_order method to take pack_size into account

- Check in existing unit test also

* Fix existing unit tests

- Previous unit test was actually in error
- Logic for calculating "on_order" was broked

* More unit tests for receiving items against a purchase order

* Allow pack_size < 1

* Display pack size when adding / editing PurchaseOrderLineItem

* Fix bug in part purchase order table

* Update part purchase order table again

* Exclude notificationmessage when exporting dataset

* Also display pack size when ordering parts from secondary form

* javascript linting

* Change user facing strings to "Pack Quantity"

InvenTree/company/migrations/0047_supplierpart_pack_size.py

@@ -0,0 +1,20 @@
+# Generated by Django 3.2.15 on 2022-09-05 04:21
+
+import InvenTree.fields
+import django.core.validators
+from django.db import migrations
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('company', '0046_alter_company_image'),
+    ]
+
+    operations = [
+        migrations.AddField(
+            model_name='supplierpart',
+            name='pack_size',
+            field=InvenTree.fields.RoundingDecimalField(decimal_places=5, default=1, help_text='Unit quantity supplied in a single pack', max_digits=15, validators=[django.core.validators.MinValueValidator(0.001)], verbose_name='Pack Quantity'),
+        ),
+    ]