rewrite charm to sidecar

[beliaev-maksim]

rewrite OIDC charm to sidecar instead of podspec

Note, there was fundamental issue (or indented feature?) that is changed now.

Before, _check_public_url was not called at all anywhere in the code. Which allowed execution without this config and made config optional

This rewrite enforces the config to be applied, otherwise unit will be in Blocked state

[i-chvets]

Integration tests pass locally:

$ tox -e integration
integration: install_deps> python -I -m pip install -r requirements-integration.txt
integration: commands[0]> pytest -v --tb native --asyncio-mode=auto /home/ichvets/cw/dev/oidc-gatekeeper-operator/tests/integration --log-cli-level=INFO -s
======================================================== test session starts =========================================================
platform linux -- Python 3.10.6, pytest-7.2.0, pluggy-1.0.0 -- /home/ichvets/cw/dev/oidc-gatekeeper-operator/.tox/integration/bin/python
cachedir: .tox/integration/.pytest_cache
rootdir: /home/ichvets/cw/dev/oidc-gatekeeper-operator, configfile: pyproject.toml
plugins: operator-0.22.0, anyio-3.6.2, asyncio-0.20.3
asyncio: mode=auto
collecting ... collected 4 items

tests/integration/test_charm.py::TestOIDCOperator::test_build 
----------------------------------------------------------- live log setup -----------------------------------------------------------
INFO     pytest_operator.plugin:plugin.py:625 Adding model uk8s:test-charm-19xa on cloud microk8s
----------------------------------------------------------- live log call ------------------------------------------------------------
INFO     pytest_operator.plugin:plugin.py:504 Using tmp_path: /home/ichvets/cw/dev/oidc-gatekeeper-operator/.tox/integration/tmp/pytest/test-charm-19xa0
INFO     pytest_operator.plugin:plugin.py:948 Building charm oidc-gatekeeper
INFO     pytest_operator.plugin:plugin.py:953 Built charm oidc-gatekeeper in 182.00s
PASSED
tests/integration/test_charm.py::TestOIDCOperator::test_deploy 
----------------------------------------------------------- live log call ------------------------------------------------------------
INFO     juju.model:model.py:1959 Deploying local:oidc-gatekeeper-0
INFO     juju.model:model.py:2582 Waiting for model:
  oidc-gatekeeper/0 [allocating] waiting: installing agent
INFO     juju.model:model.py:2582 Waiting for model:
  oidc-gatekeeper/0 [allocating] waiting: agent initializing
INFO     juju.model:model.py:2582 Waiting for model:
  oidc-gatekeeper/0 [idle] active: 
PASSED
tests/integration/test_charm.py::TestOIDCOperator::test_relations 
----------------------------------------------------------- live log call ------------------------------------------------------------
INFO     juju.model:model.py:1959 Deploying ch:amd64/focal/istio-pilot-63
INFO     juju.model:model.py:1959 Deploying ch:amd64/focal/dex-auth-224
INFO     juju.model:model.py:2582 Waiting for model:
  oidc-gatekeeper/0 [executing] active: 
  istio-pilot/0 [allocating] waiting: installing agent
  dex-auth/0 [allocating] waiting: installing agent
INFO     juju.model:model.py:2582 Waiting for model:
  istio-pilot/0 [allocating] waiting: installing agent
  dex-auth/0 [allocating] waiting: agent initializing
INFO     juju.model:model.py:2582 Waiting for model:
  istio-pilot/0 [allocating] waiting: agent initializing
  dex-auth/0 [executing] maintenance: installing charm software
INFO     juju.model:model.py:2582 Waiting for model:
  oidc-gatekeeper/0 [executing] waiting: List of oidc-client versions not found for apps: dex-auth
  istio-pilot/0 [executing] active: 
  dex-auth/0 [executing] maintenance: installing charm software
INFO     juju.model:model.py:2582 Waiting for model:
  oidc-gatekeeper/0 [idle] active: 
  istio-pilot/0 [idle] active: 
  dex-auth/0 [idle] active: 
PASSED

[i-chvets]

Approved.
ACK: CI is failing in Github runner, passes locally.

[i-chvets]

Approved.