An incorrect generation of parameter list for "CREATE SUBSCRIPTION" in Subscription class

[dmitry-lipetsk]

Documentation says - subscription_parameters must be enumerated through 'comma' symbol:

https://www.postgresql.org/docs/current/sql-createsubscription.html

CREATE SUBSCRIPTION subscription_name
    CONNECTION 'conninfo'
    PUBLICATION publication_name [, ...]
    [ WITH ( subscription_parameter [= value] [, ... ] ) ]

Subscription class does it with 'space' symbol: https://github.com/postgrespro/testgres/blob/bab1d8ec8671261787689dec99a4a3ff10499fd7/testgres/pubsub.py#L136-L142

See options_string function: https://github.com/postgrespro/testgres/blob/bab1d8ec8671261787689dec99a4a3ff10499fd7/testgres/utils.py#L265-L266

Plan

• Create the tests
• Fix a problem