refactor: update tag access in CodeGraph class to use dot notation fo…

[Lime-Cocoa]

…r attributes

[Veteran-ChengQin]

…r attributes

Brother, I modified a few more based on yours.
1、When tags is none, skip the extend operation

2、Solution: fname_part is not in s

3、Change \r to \n, because class info is separated by \n instead of \r

[Li-Lixuan]

Hey, not sure if this is a misunderstanding on my end, but the generated graph seems to have an issue. Through testing, I noticed it uses tag.name as the node identifier. However, many tags share identical tag.name, causing later tags with duplicate names to overwrite earlier ones. This results in node loss and broken dependency relationships. After adding a unique idx numbering to each tag, the problem appears resolved.