Adding test to validate network isolation.

[Mohammad-nassar10]

Implement tests to check network isolation of the fybrikmodules pods.
Closes #2055

[shlomitk1]

The test is very similar to the read test that we already have. I suggest to change the existing one to add an isolation check.

[roytman]

The test is very similar to the read test that we already have. I suggest to change the existing one to add an isolation check.

Let's leave it for now as a separate test, when we finish the isolation adaptation, we can integrate it with one of the existing tests.

[roytman]

The ArrowFlight module is very simple, it doesn't related on any external sites, except DNS and its data source". I suggest using the chaining example with airbyte module witch needs access to several external sites: docker.io, githup.com and others. I added its manifest as manager/testdata/airbyte-module-with-np.yaml

[roytman]

DNS of github is very unpredictable, can you use the DNS mock as

fybrik/manager/controllers/app/npIsolation_unit_test.go

Line 210 in 47fb207

srv, _ := mockdns.NewServer(map[string]mockdns.Zone{

, and always return one of github IPs., another option is to store the parquet files in a local HTTP server.

[roytman]

The test is not included in the CI pipeline.