Update path for pc file installation

[Spritaro]

This pull request updates the path for the pc file to ensure it is correctly installed from a subdirectory.

Currently, the install command installs the EIPScanner.pc file from CMAKE_BINARY_DIR. However, the configure_file command generates this file relative to CMAKE_CURRENT_BINARY_DIR. This causes cmake error during installation when the library is included in other projects via add_subdirectory.

To solve this, the install command has been modified to use CMAKE_CURRENT_BINARY_DIR instead of CMAKE_BINARY_DIR for the EIPScanner.pc file.

[Spritaro]

Dear Maintainers,

Thank you so much for your awesome project! I just wanted to follow up on the PR that I submitted recently. I was wondering if anyone has had a chance to review it or if there's any additional information I can provide. For reference, it's related to #95.

Best regards,
Spritaro