Fix token counts for deleted tokens

[awfm9]

When a token was deleted, i.e. we can't retrieve its details on IPFS / the HTTP server, we don't properly add the token count to the database. When a token is then transferred away from a person, it leads to a -1 entry.

The same happens when collections than re-use token IDs creates the token a second time. It might lead to entries of 2, 3 and higher if the token is transferred to the same address multiple times.

[awfm9]

This can be solved by applying the addition of the owner count on the parsing job right away, just like we do for transfers.

[awfm9]

Done in #164