Set daffodilPackageBinInfos name to root if root is defined and name is not

I would add that the DaffodilBinInfo object takes an arg named root and an arg named name, as if these concepts were orthogonal.

I don't think they should be orthogonal. Users don't need that much control.

Consider fakeTDL (on DFDLSchemas github)

Two bin files are created for each version of daffodil.

dfdl-fakeTDL-1.0.0-fakeTDL-daffodil350.bin

dfdl-fakeTDL-1.0.0-fakeTDLFile-daffodil350.bin

I don't see why the root element name isn't just always used as the classifier in the name.

I don't know why users need to be able to give alternate names like just "file" instead of putting the root element name into the file name always. But at least the default should use the root element name in the file name.

_Originally posted by @mbeckerle in https://github.com/apache/daffodil-sbt/issues/56#issuecomment-2368814355_

Start by locating daffodilPackageBinInfos and the DaffodilBinInfo handling for its root and name arguments. Use the fakeTDL example and its two generated bin filenames as the current behavior to understand. Done means the default classifier uses the root element name when root is defined and name is not, while alternate names remain possible.

Written by the indexing model from the issue text.