fix(yaml): correct merge_update_insert placeholder and update concat function parameter

Author: flarco

core/dbio/templates/base.yaml

@@ -46,7 +46,6 @@ core:
   incremental_select_limit_offset: select {fields} from {table} where ({incremental_where_cond}){where_and} order by {update_key} asc limit {limit} offset {offset}
   incremental_where: '{update_key} {gt} {value}'
   backfill_where: '{update_key} >= {start_value} and {update_key} <= {end_value}'
-  merge_update_insert: 'select error /* merge_update_insert not implemented */' 
 
 analysis:
   # table level

core/dbio/templates/exasol.yaml

@@ -191,7 +191,7 @@ bulk:
 function:
   add_months: add_months({field}, {num})
   cast: cast({field} as {type})
-  concat: concat({strings})
+  concat: concat({fields})
   date_diff_days: days_between({date1}, {date2})
   date_diff_seconds: seconds_between({date1}, {date2})
   date_parse_format: to_timestamp({string}, {format})
@@ -208,6 +208,7 @@ function:
   uuid: sys_guid()
 
 variable:
+  column_upper: true
   bool_as: string
   duplicates_group_by: false
   handle_null_compare: true