[images] Build a symbol archive if requested

This adds ninja targets symbol-archive-{zip,tgz} (that write
files symbol-archive.{zip,tgz}), in the images.json API as
{name:"symbol-archive", type:"zip"|"tgz"}.  This archive contains
a directory with an ids.txt file and all the files it points to
(with paths relative to the directory).

Bug: BLD-314 #done
Test: CQ & manual testing of symbol-archive.{zip,tgz} targets
Change-Id: I8e8382c1a91724191e9bfcc8f96cd8d187b282d4
2 files changed