feat: add support for kubeadm custom timeouts

[nicolas-goudry]

What type of PR is this?

/kind feature

What this PR does / why we need it:

This change introduces the ability to configure custom timeouts within the kubeadm configuration. It adds a new Jinja2 conditional block to include a timeouts section in the kubeadm config, based on the kubeadm_custom_timeouts variable.

• adds a conditional Jinja2 block to roles/kubernetes/control-plane/templates/kubeadm-config.v1beta4.yaml.j2 that includes a timeouts section if the kubeadm_custom_timeouts variable has content.
• the kubeadm_custom_timeouts variable's content is formatted using to_nice_yaml and indented for proper YAML structure within the timeouts section.

Which issue(s) this PR fixes:

N/A

Special notes for your reviewer:

The Timeouts section of kubeadm configuration file is only available in v1beta4.
I saw that there is an unconfigurable apiServer.timeoutForControlPlane key used in v1beta3, so I left it as-is.

This may need to be documented somewhere relevant, maybe in a new section below Kubeadm patches in docs/ansible/vars.md?

Currently, the variable is always defined and several values use the kubeadm_init_timeout variable, which makes the most sense to me. This way, we ensure that the timeouts match by default and we also allow to override them individually.
However, it's possible that the value of kubeadm_init_timeout be lower than, say, kubeadm_custom_timeouts.controlPlaneComponentHealthCheck (or vice-versa), which could cause odd issues.

Does this PR introduce a user-facing change?:

Added support for custom timeouts in kubeadm configuration (v1beta4)

[linux-foundation-easycla]

The committers listed above are authorized under a signed CLA.

• ✅ login: nicolas-goudry / name: Nicolas Goudry (ab3acca, 35239f9)

[k8s-ci-robot]

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This pull-request has been approved by: nicolas-goudry
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[k8s-ci-robot]

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