Allow to include or exclude specific sections from a file

This would allow finer control over the positioning of the sections of each file.

It should work without issues with section reordering ( decompals/slinky#44 ).

Compatibility with decompals/slinky#27 will be weird.

Syntax would look like something like this

  - name: code
    files:
      - { path: src/code/main.o }
      - { path: src/code/z_message_PAL.o, only_sections: [.data], section_order: { .data: .rodata } }
      - { path: src/code/z_game_over.o, only_sections: [.data], section_order: { .data: .rodata } }
      - { path: src/code/z_message_PAL.o, exclude_sections: [.data] }
      - { path: src/code/z_game_over.o, exclude_sections: [.data] }

Combining only_sections and exclude_sections in the same entry should be illegal.

Start by comparing the YAML examples with the section-reordering work in decompals/slinky#44 and the compatibility concern in decompals/slinky#27. Done means supporting only_sections and exclude_sections, preserving section reordering, and rejecting entries that combine both options.