host-build: add support for a stampfile per installed binary

host-build: add support for a stampfile per installed binary

Some individual build items install a group of programs
instead of a program matching the name of the build item.

Add support for installing stampfiles for each of the
programs installed by that build item,
which will allow more control and awareness
of what is installed by the rest of the build system,
if, for example, prereq symlink checks are looking
for the same program which is built already.

Signed-off-by: Michael Pratt <mcpratt@pm.me>