Since `addCustomerHeaders` middleware was after the `httpTracer`
middleware, the request ID was not set in the http tracing context. By
reordering these middleware functions, the request ID header becomes
available. We also avoid setting the tracing context key again in
`newContext`.
Bonus: All middleware functions are renamed with a "Middleware" suffix
to avoid confusion with http Handler functions.
- combine similar looking functionalities into single
handlers, and remove unnecessary proxying of the
requests at handler layer.
- remove bucket forwarding handler as part of default setup
add it only if bucket federation is enabled.
Improvements observed for 1kiB object reads.
```
-------------------
Operation: GET
Operations: 4538555 -> 4595804
* Average: +1.26% (+0.2 MiB/s) throughput, +1.26% (+190.2) obj/s
* Fastest: +4.67% (+0.7 MiB/s) throughput, +4.67% (+739.8) obj/s
* 50% Median: +1.15% (+0.2 MiB/s) throughput, +1.15% (+173.9) obj/s
```
