Better use higher-level code from common ID management when possible.
Helps to de-duplicate logic, and reduces outside usages of more
'dangerous' functions.
Note that we could get rid of many of those `BKE_<id_type>_add`
functions now, but on the other hand several of those take extra
parameters and perform additional actions, so think we can keep them all
for now as 'non-standard ID specific creation functions'.
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