[Rust] BnString::as_bytes_with_null does not include a nul byte

[bdash]

Version and Platform (required):

• Binary Ninja Version: 5.1.7320-dev (aa12054b)
• OS: macOS 15.4.1
• CPU Architecture: arm64

Bug Description:
BnString::as_bytes_with_null has no documentation, but based on its name I assumed it would include a trailing NUL. It doesn't. It returns a byte array of the string with the trailing NUL byte removed.

If it intends to include the NUL it should call through to CStr::to_bytes_with_nul rather than CStr::to_bytes.

It wouldn't hurt to update the method name to be consistent with the Rust standard library either (as -> to and null -> nul).

[emesare]

Think the mentioned PR #6789 covers this? I will just go ahead and make that the associated branch, if that is not the case we can address this in that PR.

The PR deletes these calls and just uses the underlying deref'd CStr.

[bdash]

Yes, that PR does address this.