Fix `RouterData`'s `response` construction before calling the connector

**Visible issue:**
- There are a few cases on response construction and using fields from `router_data.response` while building request, which is logically invalid.

**Changes required:**
- Check inconsistencies and make the connector request construction purely dependent on the `router_data` and `router_data.request`
- Constructing the `router_data.response` only after calling the connector