Initialize arrays of errors / error messages + minor refactoring

[FxKu]

1. In different places we are collecting errors in an array. It should be initialized correctly with make.
2. Minor refactoring in patroni_test
3. fixes Crash with 1.7.1 - nil pointer #1681

[FxKu]

Might have introduced a bug. e2e tests always fail at:

======================================================================
FAIL: test_infrastructure_roles (test_e2e.EndToEndTestCase)
Test using external secrets for infrastructure roles
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/usr/local/lib/python3.8/dist-packages/timeout_decorator/timeout_decorator.py", line 81, in new_function
    return function(*args, **kwargs)
  File "/tests/test_e2e.py", line 590, in test_infrastructure_roles
    self.eventuallyTrue(verify_role, "infrastructure role setup is not loaded")
  File "/tests/test_e2e.py", line 65, in eventuallyTrue
    self.assertTrue(f(), m)
AssertionError: False is not true : infrastructure role setup is not loaded

EDIT: Fixed, getInfrastructureRoles returned []error. When I initialize it, it fails the err != nil when the function is called. Better stick to the go convention and return only error.

[RafiaSabih]

👍

[FxKu]

👍