Missing header in local projectors

Bug description / feature request:

In the image gitlab-registry.mpcdf.mpg.de/struphy/struphy/struphy_ubuntu_latest is get the following error when compiling:

/struphy_install/env/lib/python3.12/site-packages/struphy/feec/__pyccel__/local_projectors_kernels.h:4:10: fatal error: local_projectors_args_kernels.h: No such file or directory
    4 | #include "local_projectors_args_kernels.h"
      |          ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
compilation terminated.

Expected behavior:

Compile like the other kernels.

Proposed solution:

In a kernel that imports a kernel with classes (!), which we often use for passing arguments, one needs to import the module before importing the class one intends to use. See for instance https://gitlab.mpcdf.mpg.de/struphy/struphy/-/blob/devel/src/struphy/pic/pushing/pusher_kernels.py?ref_type=heads#L11 - there is (thank me later) a comment on this.