feat: add lean_setup_libuv for initializing required LIBUV components

[algebraic-dev]

This PR adds a function called lean_setup_libuv that initializes required LIBUV components. It needs to be outside of lean_initialize_runtime_module because it requires argv and argc to work correctly.

[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 e08b2a1f62238f7f817c719e4fffcfef14243338 --onto c12159b51982221bdd66f0c5997f85e1f9d91772. You can force Mathlib CI using the force-mathlib-ci label. (2025-06-04 23:23:00)
• ❗ Batteries/Mathlib CI will not be attempted unless your PR branches off the nightly-with-mathlib branch. Try git rebase e08b2a1f62238f7f817c719e4fffcfef14243338 --onto 0a9c24649767dea857a388e5385b7ae94bfd0185. You can force Mathlib CI using the force-mathlib-ci label. (2025-06-12 16:00:12)
• ❗ Batteries/Mathlib CI will not be attempted unless your PR branches off the nightly-with-mathlib branch. Try git rebase e08b2a1f62238f7f817c719e4fffcfef14243338 --onto db499e96aac8ad654c8ed5ab40c4e6885d38c9a1. You can force Mathlib CI using the force-mathlib-ci label. (2025-06-20 23:13:14)
• ❗ Batteries/Mathlib CI will not be attempted unless your PR branches off the nightly-with-mathlib branch. Try git rebase e08b2a1f62238f7f817c719e4fffcfef14243338 --onto d3dda9f6d4428a906c096067ecb75e432afc4615. You can force Mathlib CI using the force-mathlib-ci label. (2025-06-26 13:02:30)

[eric-wieser]

This presumably makes progress on #5819 ?

[algebraic-dev]

This presumably makes progress on #5819 ?

Not exactly, LibUV provides some functions like uv_exepath that can get the executable path but it's not exactly the same as argv[0]

[TwoFX]

FFI changes LGTM except for the documentation comments. I didn't check the compiler changes.