Az networking

[Sploder12]

Adds subnets to AZs and assigns them to VMs made in that zone. This PR only covers Linux QEMU using dnsmasq.

MULTI-1942

[codecov[bot]]

Codecov Report

:x: Patch coverage is 96.05263% with 3 lines in your changes missing coverage. Please review. :white_check_mark: Project coverage is 89.50%. Comparing base (6c91f0b) to head (bf74556). :warning: Report is 8 commits behind head on availability-zones.

Files with missing lines	Patch %	Lines
...backends/qemu/linux/qemu_platform_detail_linux.cpp	94.73%	2 Missing :warning:
...tform/backends/qemu/linux/dnsmasq_process_spec.cpp	96.29%	1 Missing :warning:

Additional details and impacted files

@@                  Coverage Diff                   @@
##           availability-zones    #4071      +/-   ##
======================================================
+ Coverage               89.48%   89.50%   +0.02%     
======================================================
  Files                     268      268              
  Lines                   18003    18034      +31     
======================================================
+ Hits                    16110    16142      +32     
+ Misses                   1893     1892       -1     

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