Add Julia bindings for PaRSEC

[AddiThurston]

C wrappers plus Julia modules exposing PaRSEC's Dynamic Task Discovery (DTD) and tiled matrix APIs to Julia. Includes:

• PaRSEC4Julia package: DTD, matrix, context, runtime, and stencil modules with Julia ccall bindings (dtd_simple.jl, stencil_core.jl) over C ABI wrappers (dtd_wrapper.c, stencil_wrapper.c)
• Build system: build_parsec4julia.jl plus Project.toml, integrated into CMakeLists.txt via optional PARSEC_JULIA_BINDINGS flag
• Examples: stencil 1D, DTD GEMM, redistribute (DTD & PTG)
• Tests: DGEMM DTD accuracy and stencil 1D accuracy with MPI support via test/runtests.jl
• Stencil test utilities: Julia stencil wrapper compiles against the C stencil test sources (tests/apps/stencil) and JDF-generated stencil_1D for cross-validation with the C implementation

Made-with: Cursor
Signed-off-by: Addison Thurston on behalf of SLU's Omni Computing Lab