buf lint PACKAGE_DIRECTORY_MATCH support prefix

[manXcoder]

Feature

In the past, we managed proto files like:
aaa/aaa.proto // package name is : com.xxx.aaa

Now, with buf, we need to organize proto files like this:
com/xxx/aaa/aaa.proto

This change is required to comply with the PACKAGE_DIRECTORY_MATCH rule.

While this structure may be helpful for sharing proto files across multiple projects, it results in overly deep directory hierarchies, we need to make quite a few adjustments, especially when the protocol has already been shared with others..

If the PACKAGE_DIRECTORY_MATCH rule supported prefix matching, it would make it much easier to adapt to the buf style.