better error message when LISTEN fails in consuming

[Tirumarai Selvan]

We saw this error (on Cloud v1.3.3):

consuming input failed from postgres connection

coming from:

pg-client-hs/src/Database/PG/Query/Listen.hs

Line 65 in dd8a50c

 unless success throwConsumeFailed 

The documentation for consumeInput says use errorMessage to get the right error msg instead of printing a static text.