Fix hooks on 0.92.0

[IanManske]

Description

Fixes #12382, where overlay changes from hooks were not preserved into the global state. This was due to creating child stacks for hooks, when the global stack should have been used instead.

[kubouch]

Btw, for testing hooks, there is nu_repl_code in nu-test-support that uses the nu-repl testbing (see https://github.com/nushell/nushell/blob/main/tests/hooks/mod.rs). It might be quite dated, but might be usable if you want to add tests for this.

[IanManske]

Added a test, but it doesn't fail on current main because the nu_repl testing code has a separate implementation from the actual REPL implementation.

[FrancescElies]

This pr fixes #12382, see below the manual test.

[sholderbach]

Thanks for reporting the issue and testing the fix @FrancescElies