Rename keyIsDirectBelow to keyIsDirectlyBelow

[PhilippGackstatter]

This renames keyIsDirectBelow to keyIsDirectlyBelow as proposed in #2730 and #2979.

So this takes care of the bindings as well. For at least CPP, Java, Haskell and Rust this is a breaking change.

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[markus2330]

Thank you for creating this PR!

[markus2330]

The build server is happy now. Unfortunately, there is now a merge conflict. Can you please rebase?

[markus2330]

Something went wrong here, the file "src/bindings/haskell/src/Elektra/Key.chs" was added (but it should stay removed).

[PhilippGackstatter]

jenkins build libelektra please

[PhilippGackstatter]

jenkins build libelektra please

[PhilippGackstatter]

jenkins build libelektra please

[markus2330]

Thank you, you have really great progress!