The default import method for an asset library can now be determined in
the Preferences. The Asset Browser has a new "Follow Preferences" option
for the importing. The essentials asset library still only uses "Append
(Reuse Data)".
This is part of #104686, which aims at improving the import method
selection, especially for the introduction of the new essentials library
(which doesn't support certain import methods). Further changes are
coming to improve the UI, see #104686.
Pull Request: #104688
ae84a2956e