Add kube-apiserver-extra-sans option

[petrutlucian94]

We're adding a config option that allows specifying additional kube-apiserver Subject Alternative Names.

Applicable spec:

Overview

Rationale

Juju Events Changes

Module Changes

Library Changes

Checklist

• The charm style guide was applied
• The contributing guide was applied
• The changes are compliant with ISD054 - Managing Charm Complexity
• The documentation is generated using src-docs
• The documentation for charmhub is updated
• The PR is tagged with appropriate label (urgent, trivial, complex)

[addyess]

Can we use space separated rather than comma separated?

[github-actions]

Test coverage for f703956

coverage-report: install_deps /home/runner/work/k8s-operator/k8s-operator/charms/worker/k8s> python -I -m pip install 'coverage[toml]'
coverage-report: commands[0] /home/runner/work/k8s-operator/k8s-operator/charms/worker/k8s> coverage report
Name                                    Stmts   Miss  Cover
-----------------------------------------------------------
lib/charms/k8s/v0/k8sd_api_manager.py     278     29    90%
src/charm.py                              496    242    51%
src/cloud_integration.py                   80      3    96%
src/config/extra_args.py                   27      1    96%
src/containerd.py                         140     16    89%
src/cos_integration.py                     33     12    64%
src/events/update_status.py                51     10    80%
src/inspector.py                           40      4    90%
src/kube_control.py                        39     31    21%
src/literals.py                             6      0   100%
src/protocols.py                           26      5    81%
src/reschedule.py                          77      4    95%
src/snap.py                               185     26    86%
src/token_distributor.py                  181    109    40%
src/upgrade.py                            105     48    54%
-----------------------------------------------------------
TOTAL                                    1764    540    69%
coverage-report: OK (1.21=setup[1.00]+cmd[0.21] seconds)
congratulations :) (1.26 seconds)

Static code analysis report

Run started:2024-12-04 17:58:08.496780

Test results:
  No issues identified.

Code scanned:
  Total lines of code: 3766
  Total lines skipped (#nosec): 3
  Total potential issues skipped due to specifically being disabled (e.g., #nosec BXXX): 0

Run metrics:
  Total issues (by severity):
  	Undefined: 0
  	Low: 0
  	Medium: 0
  	High: 0
  Total issues (by confidence):
  	Undefined: 0
  	Low: 0
  	Medium: 0
  	High: 0
Files skipped (0):