Fix #2339

[tomaka]

Fix #2339

It turns out that finish panics if the data is incomplete (https://docs.rs/nom/latest/nom/trait.Finish.html#tymethod.finish)
In order to fix that, I've added the complete combinator everywhere we use finish, making sure that Incomplete errors are turned into actual errors.

[mergify]

Automatically approving tomaka's pull requests. This auto-approval will be removed once more maintainers are active.

[github-actions]

twiggy diff report

Difference in .wasm size before and after this pull request.

---

 Delta Bytes │ Item
─────────────┼────────────────────────────────────────────────────────────────────────────────────
        -252 ┊ nom::combinator::all_consuming::{{closure}}::hd3f2b064b5b0d6ee
        +252 ┊ nom::combinator::all_consuming::{{closure}}::hd7c13bd363bcbf45
        +170 ┊ <F as nom::internal::Parser<I,O,E>>::parse::h3dca017422294030
        +170 ┊ <F as nom::internal::Parser<I,O,E>>::parse::h947a6e68ce85b59f
        +170 ┊ <F as nom::internal::Parser<I,O,E>>::parse::h9f3d4cc9466ee4f2
        +170 ┊ <F as nom::internal::Parser<I,O,E>>::parse::hd951bf5e90cb34f8
        +164 ┊ <F as nom::internal::Parser<I,O,E>>::parse::hbe61107644899e2c
        +152 ┊ <F as nom::internal::Parser<I,O,E>>::parse::h6e5d3a3b85fabf1f
        +140 ┊ <F as nom::internal::Parser<I,O,E>>::parse::h7b63671bc8506863
        +138 ┊ <F as nom::internal::Parser<I,O,E>>::parse::hc94cbf5ec387739e
        +138 ┊ <F as nom::internal::Parser<I,O,E>>::parse::hd7e1fb02d8051a3e
        +116 ┊ <F as nom::internal::Parser<I,O,E>>::parse::hf0b290640b33fdf5
         -14 ┊ smoldot::network::protocol::grandpa::decode_grandpa_notification::h993ba70db16e8297
       +2464 ┊ Σ [13 Total Rows]

[melekes]

👍