Quote and escape CSV fields which contain a double-quote

Each double-quote character " gets escaped as
two double-quote characters "".
Fix typo in comment
Correct conversion from TSV to CSV in corner cases

The previous implementation merged sequences of tabs as a
single separator, skipping empty fields in non-empty lines.
Replace 'Russian Federation' with 'USSR' in AR1 institution-countries

I could reuse one existing instance of institution-{country=USSR},
and had to create two news ones where missing.

The institutions had other participations for 'Russian Federation'
and thus shall be preserved for remaining references.

Fixes #44:
https://github.com/medea-project/ipcc-database/issues/44