feat: bv_decide support for structures of supported types

[hargoniX]

This PR adds support for bv_decide to automatically split up non-recursive structures that contain information about supported types. It can be controlled using the new structures field in the bv_decide config.

[leanprover-community-bot]

Mathlib CI status (docs):

• ❗ Batteries/Mathlib CI will not be attempted unless your PR branches off the nightly-with-mathlib branch. Try git rebase 91bae2e0645bc633e3baba1b21dd3b76e032037b --onto ac6a29ee834ba7fd30e9372e51493d7741e9c657. (2025-01-21 09:15:25)
• ❗ Batteries/Mathlib CI will not be attempted unless your PR branches off the nightly-with-mathlib branch. Try git rebase 91bae2e0645bc633e3baba1b21dd3b76e032037b --onto f9e904af5022a57adb6105cda65d1569449346c2. (2025-01-21 13:41:55)