Make it possible to merge products (closes #243)

changelog/60_3.0.0_2020-12-22.md

@@ -46,6 +46,8 @@
 - The amount to be used for the "quick consume/open buttons" on the stock overview page can now be configured per product (new product option "Quick consume amount", defaults to 1)
   - This "Quick consume amount" can optionally also be used as the default on the consume page (new stock setting / top right corner settings menu)
 - Products can now be duplicated (new button on the products list page, all fields will be preset from the copied product, except the name)
+- Products can now be merged (new button on the products list page)
+  - Useful if you have two products which are basically the same and want to replace all occurrences of one with the other one
 - When consuming or opening a parent product, which is currently not in stock, any in-stock sub product will now be consumed/opened (like already automatically done when consuming recipes)
 - Opened stock entries get now consumed first by default when no specific stock entry is used/selected
   - So the default consume rule is now "Opened first, then first due first, then first in first out"
@@ -241,6 +243,7 @@
 - New endpoints GET/POST/PUT `/users/{userId}/permissions` for the new user permissions feature mentioned above
 - New endpoint `/user` to get the currently authenticated user
 - New endpoint DELETE `/user/settings/{settingKey}` to delete a user setting
+- New endpoint POST `/stock/products/{productIdToKeep}/merge/{productIdToRemove}` for the new product merging feature mentioned above
 - The following entities are now also available via the endpoint `/objects/{entity}` (only listing, no edit)
   - `stock_log` (the stock journal)
   - `stock` (the "raw" stock entries)