Extend update workflow with custom Osmium scripts to work on filtered data

[hiddewie]

Ref https://github.com/OpenSnowMap-org/data-opensnowmap.org/blob/master/tools/00_osmium_pistes_workflow.sh

Using more Osmium tools, it is possible to gather hourly/daily updates and process them into an PBF file, without using a 'default' update service. This would allow us to not store all the extra nodes / ways / relations that are received after running database updates, but only work on a filtered set.

Having such a strategy should allow us to host an entire planet railway database without using a lot of data storage (work on the filtered data).