packages: make UCL files required

[ivy]

Summary

modify template.ucl to require that the "all" UCL file exists for every
package. this prevents packages being added accidentally, and ensures
each package has as least a perfunctory comment and description.

add missing UCL files for all existing packages.

modify special packages created by Makefile.inc1 to pass the appropriate
parameters to generate-ucl to find their UCL files.