AS adapter HOCON to support set default snapshot consistency for all queries in JDBC URL

Currently AS Query operator in Streaming supports for snapshot consistency, but the setting must be at each query. and in order to do that, we need to
1. Add a field called 'consistency' to the input tuple schema, and
2. Set the value to snapshot (default is global_snapshot).

but considering:

1. TIBCO AS server setting default to Global snapshot consistency level

2. TIBCO AS adaptor default adds no config overwrite, i.e. will be global snapshot.

3. TIBCO AS engineering side recommends to use snapshot query as far as possible

due to above conflict, after our systems moved to production, and started facing performance issue, we have to do that for all query due to lack of JDBC connection level overwrite, though TIBCO AS java client supports.

So this is to suggest having a statement consistency config to be supported by AS query operator Adapter config.