Handle non-blocking TLS read retries explicitly in ssl_read_internal

[Copilot]

ssl_read_internal.cpp treated any negative return from mbedtls_ssl_read() as the same error path. This PR narrows that behavior to correctly recognize non-blocking retry states (WANT_READ / WANT_WRITE) and preserve expected read flow.

• Behavioral correction

  • Replaced broad ret < 0 handling with explicit checks for:
    • MBEDTLS_ERR_SSL_WANT_READ
    • MBEDTLS_ERR_SSL_WANT_WRITE
  • Aligns read-loop behavior with mbedTLS non-blocking semantics, avoiding misclassification of retryable conditions.

• Impact scope

  • Single-file, targeted change in:
    • src/PAL/COM/sockets/ssl/MbedTLS/ssl_read_internal.cpp
  • No API surface or protocol contract changes.

int ret = mbedtls_ssl_read(ssl, (unsigned char *)(data), size);

// before
// if (ret < 0)

// after
if (ret == MBEDTLS_ERR_SSL_WANT_READ || ret == MBEDTLS_ERR_SSL_WANT_WRITE)
{
    // retry path
}