Implement injection of particles from the embedded boundary #21084

Job	Run time
GCC 1D & 2D w/ MPI, QED tools	4m 8s
GCC 3D & RZ w/ MPI, single precision	6m 50s
GCC Minimal w/o MPI	16m 9s
GCC ABLASTR w/o MPI	1m 27s
Clang pywarpx	8m 4s
	36m 38s

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