feat: propagation of custom options, and simplification

[theangryangel]

Description

⚠️ This is WIP and experimental.

The long term plan is to provide migration paths for customers, but we make no guarantee for anyone not supported by Glo.

Several customers are interested in this suite, but there are a number of issues with the existing functionality:

• They do not require complex product restrictions and instead prefer the default exclusions UI and functionality.
  • They find configuration restrictions complex, and even the demo does not use them fully.
  • Most of our customers have only simple restrictions.
  • This PR will remove configuration restrictions in favour of exclusions
• Are confused when some options are available within the configurable products UI, but they can see configurable products in the standard inventory, and sale UIs
• They require better handling of custom options by allowing optional propagation into the stock system and beyond.
  • The canonical example is "imagine a product which is creating custom length of network cable"
  • It is important that the length is propagated through the procurement system, so that the manufacturing team know they are creating a network cable of a certain length.
  • A manufactured network cable of 5m != a manufactured network cable of 10m, and they must not ever get amalgamated together
  • Since ~13.0 the OCA / Pledra modules seem to have completely changed their original functionality
  • In some cases it is applicable to not propagate a custom option to a product.product (i.e. to ignore it). Imagine some plain text input.
  • Want the UI to integrate better with the is_custom option
  • Want the ability to support custom types and validations more clearly
    • Is it a number?
    • Is it a date?
    • Is it a regex?
    • Is it a custom Many2one?

Associated risk level High

Type of change

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• This change requires a documentation update