Add SHE (Secure Hardware Extension) support to wolfCrypt

[night1rider]

Implements software-only SHE CMD_LOAD_KEY message generation (M1/M2/M3)
and verification message computation (M4/M5) with optional crypto
callback support for hardware offload.

New files:

• wolfssl/wolfcrypt/she.h: API declarations, constants, wc_SHE context
• wolfcrypt/src/she.c: Miyaguchi-Preneel KDF, message generation,
  verification computation, and crypto callback integration
• tests/api/test_she.c/h: API tests with 97% line / 100% function coverage

API:

• wc_SHE_Init/Free, Init_Id, Init_Label (lifecycle)
• wc_SHE_GenerateM1M2M3 (generate M1/M2/M3 to caller buffers, callback optional)
• wc_SHE_GenerateM4M5 (generate M4/M5 to caller buffers, independent of
  M1/M2/M3, callback optional)
• wc_SHE_ImportM1M2M3 (import external M1/M2/M3 into context)
• wc_SHE_GetUID (callback required, fetches UID from hardware)
• wc_SHE_GetCounter (callback required, reads monotonic counter from hardware)
• wc_SHE_ExportKey (callback required, exports key slot as M1-M5 from hardware)
• wc_SHE_SetKdfConstants (callback optional, WOLFSSL_SHE_EXTENDED only)
• wc_SHE_SetM2Header (callback optional, WOLFSSL_SHE_EXTENDED only)
• wc_SHE_SetM4Header (callback optional, WOLFSSL_SHE_EXTENDED only)
• No key material stored in the context; all inputs passed at generation time

Crypto callback integration:

• WC_ALGO_TYPE_SHE added to wc_AlgoType enum
• Callback sub-types: WC_SHE_SET_UID, WC_SHE_GET_COUNTER,
  WC_SHE_GENERATE_M1M2M3, WC_SHE_GENERATE_M4M5, WC_SHE_EXPORT_KEY
• Per-operation structs in wc_CryptoInfo union with full parameter passthrough
• Dispatch functions in cryptocb.c
• Optional features: NO_WC_SHE_GETUID, NO_WC_SHE_GETCOUNTER,
  NO_WC_SHE_EXPORTKEY, NO_WC_SHE_IMPORT_M123

Build system:

• configure.ac: --enable-she=standard|extended
• CMakeLists.txt: WOLFSSL_SHE standard|extended|no
• src/include.am: she.c compilation
• .github/workflows/os-check.yml: CI configs for standard, extended,
  and NO_* disable flag combinations

Ported from wolfHSM wh_she_crypto.c.