Adds keyboard shortcuts (currently `n` and `N`) in the diffing plugin
view to jump to the next/prev difference in the list.
IMPORTANT NOTE: Depends on changes made in a library submodule. [This
PR](https://github.com/WerWolv/libwolv/pull/34) must be accepted first.
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Co-authored-by: Nik <werwolv98@gmail.com>