Address indicator displays invalid file offsets for non-file-backed addresses

[ElykDeer]

Version and Platform (required):

• Binary Ninja Version: 6.0.10526-dev
• Edition: Ultimate
• OS: OSX
• OS Version: 26.5.2
• CPU Architecture: M3

Bug Description:
With the address indicator in the bottom right set to File Offset mode, navigating to an address that is not backed by file data displays an invalid file offset. Linear shows an offset from the beginning of the section, which I think we should mirror in the bottom right.

Steps To Reproduce:

1. Navigate to the .bss of any binary
2. Right-click the address indicator in the bottom right and select Display Format > File Offset
3. See the invalid file offset

Expected Behavior:
If an address is not backed by the file and can't have a file offset, I think the next best thing for us to show is the section-relative offset or just Not part of any file.