Add cmake option to compile AIrouter

cmake  -DAIROUTER=true

if you want to use AIRouter.
(CGAL should be installed)
4 jobs for develop in 9 minutes and 51 seconds (queued for 9 seconds)
Status Job ID Name Coverage
  Configure
passed #35800
linux
configure-linux

00:00:14

 
  Compile
passed #35801
linux
make-linux

00:09:03

 
  Unit Test
passed #35802
linux
test

00:00:18

 
  Juelich Tests
failed #35803
linux
verification

00:00:14

 
Name Stage Failure
failed
verification Juelich Tests
	 25 - runtest_juelich_5 (Failed)
26 - runtest_juelich_6 (Failed)
27 - runtest_juelich_8 (Failed)
28 - runtest_juelich_9 (Failed)
Errors while running CTest
Running after script...
$ echo "End CI"
End CI
ERROR: Job failed: exit code 1