FR: Customization of subtypes in the account balance

[IncogVito]

Describe the feature

Users should be able to create their own subtypes. The most suitable location for this editor would be under General → Types

Why is this feature important?

When adding a new balance account (investment), the available subtypes don’t fully match my needs. By making subtypes configurable and storing them in the database, the application would better adapt to user requirements

Additional context, screenshots, and relevant links

So far it's done with static subtypes like:

sure/app/models/investment.rb

Line 16 in 617876f

}.freeze