PKCS7: accept any BIO type for detached content in PKCS7_verify

[kojo1]

Description

wolfSSL_PKCS7_verify() pulled the detached content out of the input
BIO with wolfSSL_BIO_get_mem_data(), which only handles memory BIOs.
With a file BIO it returned 0 bytes instead of an error, so the
content was treated as empty and verification failed. The returned
pointer also came from the WOLFSSL_BIO ptr union, which holds the
XFILE handle for a file BIO.

Fixes zd#22345

Testing

Added test_wolfSSL_PKCS7_verify_detached_bio()

Checklist

• added tests
• updated/added doxygen
• updated appropriate READMEs
• Updated manual and documentation

[github-actions]

MemBrowse Memory Report

gcc-arm-cortex-m4

• FLASH: .text +128 B (+0.1%, 204,893 B / 262,144 B, total: 78% used)

gcc-arm-cortex-m4-openssl-compat

• FLASH: .rodata -80 B, .text +1,408 B (+0.2%, 782,236 B / 1,048,576 B, total: 75% used)

gcc-arm-cortex-m4-pkcs7

• FLASH: .text +64 B (+0.0%, 217,628 B / 262,144 B, total: 83% used)

gcc-arm-cortex-m4-rsa-only

• FLASH: .text +128 B (+0.0%, 331,936 B / 1,048,576 B, total: 32% used)

gcc-arm-cortex-m7

• FLASH: .text +128 B (+0.1%, 204,893 B / 262,144 B, total: 78% used)

linuxkm-pie

• Data: __patchable_function_entries +8 B (+0.0%, 26,992 B)

linuxkm-standard

• Data: __patchable_function_entries +8 B (+0.0%, 49,776 B)
  No memory changes detected for:
• gcc-arm-cortex-m0plus
• gcc-arm-cortex-m3
• gcc-arm-cortex-m4-baremetal
• gcc-arm-cortex-m4-crypto-only
• gcc-arm-cortex-m4-dtls13
• gcc-arm-cortex-m4-min-ecc
• gcc-arm-cortex-m4-pq
• gcc-arm-cortex-m4-sp-math
• gcc-arm-cortex-m4-tls12
• gcc-arm-cortex-m4-tls13
• gcc-arm-cortex-m7-pq
• gcc-arm-cortex-m7-tls13
• stm32-sim-stm32h753