refactor: normalize abstract interface and concrete service

src/taxpasta/domain/service/taxonomy_service.py

@@ -55,6 +55,10 @@ def get_taxon_name_lineage(self, taxonomy_id: int) -> Optional[List[str]]:
     def get_taxon_identifier_lineage(self, taxonomy_id: int) -> Optional[List[int]]:
         """Return the lineage of a given taxonomy identifier as identifiers."""
 
+    @abstractmethod
+    def get_taxon_rank_lineage(self, taxonomy_id: int) -> Optional[List[str]]:
+        """Return the lineage of a given taxonomy identifier as ranks."""
+
     @abstractmethod
     def add_name(self, table: DataFrame[ResultTable]) -> DataFrame[ResultTable]:
         """Add a column for the taxon name to the given table."""
@@ -73,6 +77,10 @@ def add_identifier_lineage(
     ) -> DataFrame[ResultTable]:
         """Add a column for the taxon lineage as identifiers to the given table."""
 
+    @abstractmethod
+    def add_rank_lineage(self, table: DataFrame[ResultTable]) -> DataFrame[ResultTable]:
+        """Add a column for the taxon lineage as ranks to the given table."""
+
     @abstractmethod
     def summarise_at(
         self, profile: DataFrame[StandardProfile], rank: str

src/taxpasta/infrastructure/domain/service/taxopy_taxonomy_service.py

@@ -84,7 +84,7 @@ def get_taxon_identifier_lineage(self, taxonomy_id: int) -> Optional[List[int]]:
         return taxon.taxid_lineage
 
     def get_taxon_rank_lineage(self, taxonomy_id: int) -> Optional[List[str]]:
-        """Return the lineage of ranks of a given taxonomy identifier."""
+        """Return the lineage of a given taxonomy identifier as ranks."""
         try:
             taxon = taxopy.Taxon(taxid=taxonomy_id, taxdb=self._tax_db)
         except TaxidError:
@@ -150,7 +150,7 @@ def _taxid_lineage_as_str(self, taxonomy_id: int) -> Optional[str]:
         return ";".join([str(tax_id) for tax_id in taxon.taxid_lineage])
 
     def add_rank_lineage(self, table: DataFrame[ResultTable]) -> DataFrame[ResultTable]:
-        """Add a column for the taxon rank lineage to the given table."""
+        """Add a column for the taxon lineage as ranks to the given table."""
         result = table.copy()
         result.insert(
             1,