[FR] Convert more server-side forms to the API

[SchrodingersGat]

Convert the forms missed in #2198

Refactoring existing "StockItem" forms to use the API forms architecture

Closes #1905

• ValidateBOM form - Duplicate bom form #2477
• Merge stock items - Add ability to merge stock items #346
• Assign to Customer form - [FR] Add ability to assign multiple stock items to a customer #2369
• Install stock item - Install into fixes #2640
• Uninstall stock item - Converting more forms to the API #2931
• Add / improve unit testing for new forms
• Add placeholder text for serial numbers when creating a new stock item - Serial number placeholders #2370
• Add placeholder text for serial numbers when serializing a stock item
• Reimplement unit testing for stock item serialization
• Build cancel - Converting more forms to the API #2931
• Build complete - Adds confirmation inputs when completing build order #2510
• New build output - Build serial number magic #2631
• Delete build output(s) - Delete multiple outputs #2615
• Issue purchase order - Converting more forms to the API #2931
• complete purchase order - Converting more forms to the API #2931
• cancel purchase order - Converting more forms to the API #2931
• cancel sales order - Converting more forms to the API #2931
• ship sales order - Create SalesOrderShipment model #2199
• duplicate BOM - Duplicate bom form #2477
• export BOM - BOM export form fixes #2452
• Add related part - Related part api #2361
• Delete related part - Related part api #2361
• Return from Customer form - Return from customer #3120
• Delete part - Delete part via API #3135
• Delete build order - Allow build orders to be deleted via the API #3155
• Delete part category - Converting more forms to the API #3181
• Delete stock location - Converting more forms to the API #3181
• Delete stock item - Converting more forms to the API #3181
• Delete stock item tracking - Remove outdated forms / views for stock item tracking #3122
• Edit stock item tracking - Remove outdated forms / views for stock item tracking #3122
• Create stock item tracking - Remove outdated forms / views for stock item tracking #3122
• Delete part parameter template - Move PartParameterTemplate model to the API #3123
• Create part parameter template - Move PartParameterTemplate model to the API #3123
• Edit part parameter template - Move PartParameterTemplate model to the API #3123
• Part set category - Set part category #3134
• Convert to variant form - Migrate "Convert to Variant" form to the API #3183
• Create category template - Convert category parameter forms to use the API #3130
• Edit category template - Convert category parameter forms to use the API #3130
• Delete category template - Convert category parameter forms to use the API #3130
• Delete test data associated with stock item - Refactor stock item test result form for API #3143
• Delete supplier part
• Delete manufacturer part

[SchrodingersGat]

The remaining forms here will have to wait for 0.8.0