fix: fix handling of loading empty metadata file for queue

[Mantisus]

Description

• Error handling if an empty metadata file was created
• Reduced the probability of creating empty metadata files

Issues

• Closes: error starting up crawlee - json.decoder.JSONDecodeError: Expecting value #1029

[Pijukatel]

Could you please add some test that would capture the nature of this scenario.

[Pijukatel]

If the file exists we can still open it with "wb" mode.If we open it with "r+b" mode, then we are not overwriting the whole file with new content but just changing the file starting from the beginning of the file. I doubt that is what we want.

Imagine file with content b"abc"
and you want to change it

with open(path, 'r+b') as f:
    f.write(b"x") 

-> b"xbc"

with open(path, 'wb') as f:
    f.write(b"x") 

-> b"x"

Maybe I have missed the point here, but so far it does not seem right to me.