Task/499 network part of issue

### Description
o Fixed the 'network part' of issue #499 (part 1 of uncached queries/updates for context providers).

o About adding CB_PORT as preferred variable to BROKER_PORT, doing the FULL change, i.e. completely stop using BROKER_PORT etc is a too big task to include in this PR. I tried but it got BIG. Coming in a PR soon.

o About statistics, I have passed completely on the statistics in this PR. There are two new messages 'QueryContextResponse' and 'UpdateContextResponse' but they are NOT included in the statistics. Perhaps this was not a good idea, and it is easy enough to include them. However, I have a feeling the entire statistics concept needs to be looked over ...

o I had some problems with the compiler copying entire vectors, in the clone/fill functions. I changed a few of them from 'const Class&' to 'Class*'. Also, I changed the name 'clone' to 'fill' for the methods that don't actually clone anything (methods that just fill).

Is the follwoing correct?

```
# 12. Query broker for E1/A1 (will go to CP1 and it will work, A1=CP1 is returned)
# 13. Query broker for E1/A2 (will go to CP2 and it will work, A1=CP2 is returned)
# 14. Query broker for E1/A3 (will go to CP3 and it will work, A1=CP3 is returned)
# 15. Update/UPDATE E1/A1(=CP1-2) in CB (is forwarded to CP1 and now it is updated)
# 16. Update/UPDATE E1/A2(=CP2-2) in CB (is forwarded to CP2 and now it is updated)
# 17. Update/UPDATE E1/A3(=CP3-2) in CB (is forwarded to CP3 and now it is updated)
# 18. Query broker for E1/A1 (will go to CP1 and it will work, A1=CP1-1 is returned)
# 19. Query broker for E1/A2 (will go to CP2 and it will work, A2=CP2-2 is returned)
# 20. Query broker for E1/A3 (will go to CP3 and it will work, A3=CP3-2 is returned)
```

In that case, I will use that lines to enhance precission (including updating `echo` messages). Probably a dull work now but we will thank it in the future if we need to debug :)