add find by label spec. *

* Should use a dedicated class instead of Multicriteria filter.
Would probably needs as well to be moved in a shared example.
Lookup plate by label works but break others. *

* Needs refactoring
Add pack/unpac_uuid to Labellable persistors
All spec passes. needs refactoring
Refactor label filter specs
Share label filtrage specs.
[fixes #42211553] Use label filter in CreateSearch
Merge pull request #79 from maxigit/42211553_lookup_labellabe_by_barcode

42211553 lookup labellabe by barcode