Add c/ directories with EverParse 3D generation for 15 Wire packages
Creates c/gen.ml + c/dune + generated .3d files for every package
that defines Wire codecs. Each gen.ml calls Wire_3d.main to project
the OCaml Wire codec definition to EverParse 3D format.
Packages: FSR, PUS, GPT, MBR, PID1, LTP, TCPCL (8 codecs), UDPCL,
AX.25, CFDP (3 fixed-size codecs), SDLS (EP header + MC status),
SpaceWire, RPMsg, SquashFS (5 codecs), SpaceFibre.
Codecs with Wire.Param.input (variable-size) are excluded from 3D
generation: CFDP header/eof/metadata/keep-alive, SDLS security
header/trailer, PUS tm_header/hk_param.
Proximity-1 and space-wire excluded: proximity-1 has only variable-
size codecs, space-wire has its own C generation approach.
Fixes E900 (17→2) and E905 (remaining MBR Partition.struct_).