[FLOSS] storage plugins: fail on unknown metadata

[markus2330]

Currently most of the storage plugins simply eat unknown metadata. They should fail with an error instead.

I.e. kdb meta-set user:/mp blue blah

should either fail or kdb meta-get user:/mp blue should return blah

• [x] #4579
• [x] #4581
• [x] #4586
• [x] #4582
• [x] #4583
• [x] #4584
• [x] #4580
• [x] #4585

[Bujuhu]

I've looked at every storage plugin except those, who discourage or omit mounting / setting values for keys altogether. I've created a single issue for every plugin I found which behaves that way. Creating a single issue for each one might seem kind of silly, seeing how similar they are, but I think it makes more sense that way, as most of the plugins probably won't be fixed all simultaneously.

[markus2330]

Great job! I linked all issues in the top post and ordered them by priority.

[markus2330]

We should mark the buggy plugins or remove them. @atmaxinger what do you think?