CLOUDSTACK-8685: Fix for missing defaultroute on VPC router https://issues.apache.org/jira/browse/CLOUDSTACK-8685

Refactored CsRoute and CsAddress to:
 - add methods to add and verify the defaultroute
 - renamed methods flush, add, and routeTable to flush_table, add_route, add_table respectively.

Added some suboptimal unit tests to TestCsRoutes

* pr/738:
  Fixed defaultroute on VPC routers in CsRoute and CsAddress Refactored CsRoute
  pep8 cleanup

Signed-off-by: Remi Bergsma <github@remi.nl>

[BLOCKER] Combined PRs that fix VR issuesTonight I worked with @wilderrodrigues to figure out what is wrong with the virtual router. As we couldn't test single PRs any more (because of other issues with them causing tests to fail) we added all VR related PRs in a separate branch and started testing from there.

We combined the following PRs into this PR:
#836 #851 #867 #870 #881 #882 #842

After that, one issue remains: the VPC does not get a default gateway. Which is strange, because we already solved it in PR #738. When I look back, it was fixed again in PR #784. It could very well be that either one fixed one specific case, but also breaking the other. We need to investigate this, and make sure there will be a fix that works both for VPCs and VRs.

When we manually add the default gateway on the VPC, most tests pass and also spinning up two VPCs with one tier each, having a VM and them using s2s to VPN them together works fine. See for more details the report Wilder sent earlier.

Tomorrow we'll try to figure out how to fix the default gateway and merge this. Then we should have a base to work from again. Any PR that fixes another blocker, should at least then be rebased against the fixed master so we can run the tests against the PR branch. I'm not saying everything is fixed, I'm just saying that we can spin up a cloud that has working VMs.

When, in the mean time, someone has the time to checkout this branch and make the default route work for both VPC and VR that would be awesome. After that we should double check and verify the test results.

Pinging @karuturi to let her know the current status.

Regards,
Wilder / Remi

* pr/887:
  Fixing the index out of bounds error in the check_if_link_up() function
  small cleanups
  Fixing the defaut route for VPC routers
  Formatting the get_gateway() method in the CsDatabag.py file
  Fixing the dhcpsrvr iptables file
  Formatting the router_proxy.sh script
  CLOUDSTACK-8881: Fixed Static and PF configuration issue
  CLOUDSTACK-8905: Fixed hooking egress rules
  CLOUDSTACK-8891: Fixed default iptables rules on VR  for guest traffic
  Configured dnsmasq to listen on all interfaces so that vpn  client gets dns
  CLOUDSTACK-8864: Not able to add TCP port forwarding rule in VPN for specific ports
  CLOUDSTACK-8863: VM doesn't reconnect to internet post VR RESTART/STOP-START/RECREATE
  CLOUDSTACK-8843: Fixed issue in default iptables rules on shared network VR

Signed-off-by: Remi Bergsma <github@remi.nl>

Co-authored-by: Pearl Dsilva <pearl.dsilva@shapeblue.com>
Signed-off-by: Rohit Yadav <rohit.yadav@shapeblue.com>