location-importer.in: import additional IP information for Amazon AWS IP networks

location-importer.in: import additional IP information for Amazon AWS IP networks

Amazon publishes information regarding some of their IP networks
primarily used for AWS cloud services in a machine-readable format. To
improve libloc lookup results for these, we have little choice other
than importing and parsing them.

Unfortunately, there seems to be no machine-readable list of the
locations of their data centers or availability zones available. If
there _is_ any, please let the author know.

The second version of this patch adds a meaningful description for the
"source" column in the overrides tables, to make introduced changes
less intransparent.

Fixes: #12594
Signed-off-by: Peter Müller <peter.mueller@ipfire.org>
Signed-off-by: Michael Tremer <michael.tremer@ipfire.org>