Add * support products and modules

Passing "*" to --products is equivalent to passing the all_named_producs
build variable

Passing "*" to --modules passes the contents of
PRODUCT_OUT/all_modules.txt

The total length of the text of all_modules can easily exceed the
maximum argument size for the OS. The proper solution is likely to call
getconf ARG_MAX, then concatenate the command to be executed to check
against the limit. Instead, the modules are processed in batches of 40k
modules. As long as module names don't get extremely long, this should
keep us under the ARG_MAX limit. In testing, using --modules "*" gets
split into two batches.

Test: build/make/tools/whichgit --modules "*"
Test: build/make/tools/whichgit --modules "*" --unused
Test: build/make/tools/whichgit --modules "*" --products "*"

Existing use-cases should remain unchanged:

TEST: build/make/tools/whichgit --modules framework
Change-Id: Ifa947daea2d439df0145e6def92637b67a8b5d22