Make debuginfo endpoint more resilient

[philippguertler]

Gentics Mesh Version, operating system, or hardware.

• v1.7.x

Problem

The debug endpoint is a combination of different debug info providers. Each of these providers could fail and this currently causes the downloaded zip file to be corrupted.

Expected behaviour and actual behaviour

I expect failing providers to not entirely corrupt the resulting zip file. Instead, the information from the failing provider should just be omitted in the end result.