fdo#75757: remove inheritance to std::map

Change-Id: I2fd0b43c62c331d866d697c94dd57d17f903111b
Reviewed-on: https://gerrit.libreoffice.org/10810
Reviewed-by: David Tardon <dtardon@redhat.com>
Tested-by: David Tardon <dtardon@redhat.com>