This time we don't need to catch permission errors and such since we're reading it from a string that was stored in memory (read when the preferences file was read). However we do need to catch JSON Decoding Errors since the JSON syntax might be broken by the user modifying these files or because the file wasn't saved properly before.
Fixes Sentry issue CURA-112.
It was decided that functionality present in existing plugins is
sufficient. No need to replicate it in our own codebase and
take on the burden of maintenance
CURA-5479
