feat: add identifier panel in pubchem page (#20)

* feat: show identifier summary

with Luc we discussed that it might be useful to show some basic identifiers
and a link to Pubchem to give users the possibility
to verify that we retrieved the information for the correct compound.

i noticed that the labels are not optimal atm.
I'll fix this upstream in the Pubchem package.

* feat: also show structure and description

* chore: remove lint