With this commit we reduce heap usage of the ingest-geoip plugin by
memory-mapping the database files. Previously, we have stored these
files gzip-compressed but this has resulted that data are loaded on the
heap.
Closes#28782
The database files have been doubled in size compared to the previous files being used.
For this reason the database files are now gzip compressed, which required using
`GZIPInputStream` when loading database files.
Daniel Mitterdorfer
Sian Lerk Lau
Martijn van Groningen
Sylwester Lachiewicz