Redo build system based on ida-sdk repository

[mrexodia]

Tested on macos aarch64, but should work fine on Windows/Linux as well.

The following commands should compile the loader and xex1tool out of the box on every platform and install it into IDAUSR so you can use the plugin:

# Submodules
git submodule update --init

# Compile
cmake -B build -DCMAKE_BUILD_TYPE=Release
cmake --build build --config Release

# Install
cmake --install build --config Release

Note: this depends on emoose/ExCrypt#15 so I pointed the submodule to my repo until that is merged. Happy to fix up later.

[emoose]

Gave it a try and looks like it's working fine with IDA 9.4 Windows here, happy to merge!

Also just merged your ExCrypt PR if you want to update the submodule here

[mrexodia]

Alright, updated the submodule! FYI #19 needs some rebasing once this is merged