Added handler for 'template' metadata
Added handler for 'template' metadata

Similar user defined metadata are also handled togheter

Signed-off-by: Miklos Vajna <16f13092e03e3d9e997de904d0f86cc803fb6ef7@collabora.co.uk>

Distrotech/libodfgen,Distrotech/libodfgen,Distrotech/libodfgen