Added tests for the situations where a citizen is already authenticated and has already attempted to sign the proposal and the existing signature is at the 'invalid return', 'too late' or 'repeated_returning' state.
Added tests for the situations where a citizen is already authenticated and has already attempted to sign the proposal and the existing signature is at the 'invalid return', 'too late' or 'repeated_returning' state.

avoinministerio/avoinministerio,avoinministerio/avoinministerio