unroll strain features to strain level, possibly with disconnected taxa

[realmarcin]

☒ Strain creat ☒ Feature link ☒ No NCBITaxon ✔ Submit →

Review your answers ● Should strain nodes ALWAYS be created for every BacDive record, or only when TYPE_STRAIN == 'yes'? → Always create strain nodes for every BacDive record ● When a strain node is created, should features EVER be linked to the parent NCBITaxon species, or ONLY to the strain node? → Only link to strain node ● When there's NO NCBITaxon ID at all (neither species nor strain level), what should happen? → Still create strain node and link features to it