Replace pyff by a simple bash script

[baszoetekouw]

Pyff's memory requirements are ridiculous, and not suitable for the SC docker environment. Therefore, let's just replace Pyff by a simple bash script that selects the correct entities and resigns the XML.

We could then move the scripts from a docker how to a regular SURFconext management host.
As a bonus, this would make metadata signing using HSMs possible.

See https://gitlab.surf.nl/surfconext/surfconext-metadata-publish for inspiration on how SURFconext handles this (specifically the sign_metadata.sh scrip)t.

[mrvanes]

https://github.com/SURFscz/SRAM-metadata-parser

[baszoetekouw]

This needs to be deployed for test2.

[baszoetekouw]

We have an update metadata tools machine for SC, lets put in on there. For the old TAP, we keep the current metadata servicer.