Rename DEBUG enum variants

[lelandjansen]

Many C++ build systems define DEBUG=1 to signify when they're building in debug mode. Variables, enum variants, etc. named DEBUG are subject to this macro substitution, get renamed to 1, and fail to compile. This PR renames DEBUG enum variants to a similar name that doesn't get substituted by the preprocessor.

Test plan

mkdir build
cd build
cmake -DCMAKE_BUILD_TYPE=Release ..
cmake --build . --target LIB_LIEF --config Release

[romainthomas]

Looks good, I'll take a closer CI-review in two days!

[romainthomas]

@lelandjansen thank you for your PR. I did some update on the Python side and I merged through ef824c7

[lelandjansen]

Thank you @romainthomas!