Clarify collation mismatch string (#20641)

We replace expected/received with the source of the collation.

This makes it more clear as to from where the values
were retrieved.

```release-note
NONE
```

store/sqlstore/store.go

@@ -1167,7 +1167,7 @@ func (ss *SqlStore) ensureDatabaseCollation() error {
 		}
 
 		if tableCollation != connCollation.Value {
-			mlog.Warn("Table collation mismatch", mlog.String("table_name", tableName), mlog.String("expected", connCollation.Value), mlog.String("found", tableCollation))
+			mlog.Warn("Table collation mismatch", mlog.String("table_name", tableName), mlog.String("connection_collation", connCollation.Value), mlog.String("table_collation", tableCollation))
 		}
 	}