feat: refactor authentication flows inside of the webhook (#225)

* Refactor authentication flow in the webhook.

Remove the obsolete long-live token authentication option.
Add the possibility to setup multitenant environment using SA keys per namespace.
Add the possibility to use WIF auth flow.

* Add integration test for the multitenant auth flow.

* Update documentation

* fix: code review

* fix: lint and lower acme record default TTL

Bump appVersion and version to 0.5.0

Bump appVersion and version to 0.5.0

Bump appVersion and version to 0.4.11

Bump appVersion and version to 0.4.11

chore: renovate - set minimum release age

Update Chart.yaml

release new version 0.4.10

Update Chart.yaml

release new version 0.4.10

Update Chart.yaml

fix wrong chart version number

Merge pull request #204 from stackitcloud/renovate/all-minor-patch

chore(deps): update all non-major dependencies