fix: test: Rewrite views/addzone in loop system test

A part of the `views` system test attempts to add multiples zones in a
loop, and after each zone being added, reconfig the server.

However, the test didn't take into account the fact that the server
might take a bit more time to reload than the script to move to the next
iteration, and in some case the test was re-requesting the server reload
when it was still reloading.

Since `b49f83a3`, `named` explicitly fails to reload when a load/reload
is pending, which is (unless proved otherwise) the reason of the test
was now randomly failing.

That part of the test is now waiting for the server log message saying
the server has added the new zone and is running. Also, that part of the
test has been rewrote in Python.

Closes #5617

Merge branch '5617-rewrite-reload-view-test' into 'main'

See merge request isc-projects/bind9!11225