`entryName` only rejected NUL and over-long names, so whatever an archive called an entry flowed
straight into `FullPath`, the file tree and every encoder.
- a name containing `!/` could pose as a nested archive boundary and collide with a real nested entry
- control characters and unicode line separators could add lines to SPDX tag-value output
Both are now refused, and refused names (over-long ones included) mark the resolver truncated with
the quoted name instead of being dropped silently.
Signed-off-by: Alex Goodman <wagoodman@users.noreply.github.com>