Add CUDA GPU coredump support to nvproxy

Adds the five missing `ioctls` required to generate [CUDA GPU coredumps](https://docs.nvidia.com/cuda/cuda-gdb/index.html#gpu-core-dump-support) (`CUDA_ENABLE_COREDUMP_ON_EXCEPTION=1`) under nvproxy, all on the `GT200_DEBUGGER` (`0x83de`) class:

- `NV83DE_CTRL_CMD_DEBUG_SET_MODE_MMU_DEBUG` (`0x83de0307`) control command — enables MMU debug mode during exception handling.
- `NV83DE_CTRL_CMD_DEBUG_READ_MEMORY` (`0x83de0315`) control command, with its `NV83DE_CTRL_DEBUG_READ_MEMORY_PARAMS` struct — reads a block of memory from the debugged context into an embedded pointer (`buffer`), which requires a custom handler. Note that the driver passes `RMAPI_PARAM_COPY_FLAGS_DISABLE_MAX_SIZE_CHECK` for this control (see `src/nvidia/src/kernel/rmapi/embedded_param_copy.c`), so unlike most embedded pointers the buffer is *not* bounded by `RMAPI_PARAM_COPY_MAX_PARAMS_SIZE`; the handler mirrors this.
- `NV83DE_CTRL_CMD_DEBUG_SUSPEND_CONTEXT` (`0x83de0317`) control command — suspends the faulting SM context so its state can be captured.
- `NV83DE_CTRL_CMD_DEBUG_RESUME_CONTEXT` (`0x83de0318`) control command — resumes the context after capture. No params.
- `NV83DE_CTRL_CMD_DEBUG_SET_MODE_ERRBAR_DEBUG` (`0x83de031f`) control command — enables error-barrier debug mode (Volta+), a prerequisite for capturing SM exception state.

All are simple pass-through controls except `DEBUG_READ_MEMORY`. They are gated on `compute,utility`, consistent with the existing `NV83DE` debug controls (`SET_EXCEPTION_MASK`, `READ_ALL_SM_ERROR_STATES`, `CLEAR_ALL_SM_ERROR_STATES`).

Coredump generation additionally uses `NV2080_CTRL_CMD_GPU_EXEC_REG_OPS` (already supported), so the feature requires running with `--nvproxy-allowed-driver-capabilities=all,profiling`.

Tested on an A10G with a faulting Triton kernel: the generated `.nvcudmp` matches native (runc) byte-for-byte in size, and `cuda-gdb` fully decodes it (`CUDA Exception: Warp Illegal Address`, faulting PC/kernel/warp/lane and backtrace). Without this change, coredump generation silently produces an empty dump (`No exception was found on any device`).

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