Adds support for IN operator as adhoc filter

[Kenterfie]

This merge request adds a missing feature, which we have actively used in the past with the Altinity Grafana datasource. In general it allows adhoc filters which make use of the IN operator.

This issue is also addressed in https://github.com/grafana/clickhouse-datasource/issues/883

Example adhoc filter

key = ipv4Dst
operator = IN
value = ('1.1.1.xxx','2.2.2.xxx')

Expected additional filter settings additional_table_filters={'table' : ' ipv4Dst IN (\'1.1.1.xxx\',\'2.2.2.xxx\')'}

Current additional filter output settings additional_table_filters={'table' : ' ipv4Dst IN \'('1.1.1.xxx','2.2.2.xxx')\' '}