support/scripts/pkg-stats: show progress of upstream URL and latest version

support/scripts/pkg-stats: show progress of upstream URL and latest version

This commit slightly improves the output of pkg-stats by showing the
progress of the upstream URL checks and latest version retrieval, on a
package basis:

Checking URL status
[0001/0062] curlpp
[0002/0062] cmocka
[0003/0062] snappy
[0004/0062] nload
[...]
[0060/0062] librtas
[0061/0062] libsilk
[0062/0062] jhead
Getting latest versions ...
[0001/0064] libglob
[0002/0064] perl-http-daemon
[0003/0064] shadowsocks-libev
[...]
[0061/0064] lua-flu
[0062/0064] python-aiohttp-security
[0063/0064] ljlinenoise
[0064/0064] matchbox-lib

Note that the above sample was run on 64 packages. Only 62 packages
appear for the URL status check, because packages that do not have any
URL in their Config.in file, or don't have any Config.in file at all,
are not checked and therefore not accounted.

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>