feat: enhance library file packaging

[gzg1023]

I'm using vite as a development build tool for lib projects. In vite, you can use lib to develop the file entry and the variable name or build type,but there is no fileName specified
I read the source code and found that the field is a direct way to get the name field of package.json.I think a new fileName field should be added to specify the name of the output file after packaging, and the default value can be the name of package.json

otherwise I would need to manually change the names of the different types of files after each build is completed.
Because the nane of my package.json is not necessarily the name I need.

I added a field for the lib configuration. See #2475 for details