feat: Generate self-signed certs with SAN

[simster7]

This should fix the CN certificate invalid issue.

Taking Golang's lead from https://github.com/golang/go/blob/ba9e10889976025ee1d027db6b1cad383ec56de8/src/crypto/tls/generate_cert.go as suggested by golang/go#39568 (comment)

[codecov]

Codecov Report

Merging #5571 (32ed5a3) into master (2b3655e) will increase coverage by 0.13%.
The diff coverage is n/a.

❗ Current head 32ed5a3 differs from pull request most recent head 93dbda9. Consider uploading reports for the commit 93dbda9 to get more accurate results

@@            Coverage Diff             @@
##           master    #5571      +/-   ##
==========================================
+ Coverage   46.94%   47.08%   +0.13%     
==========================================
  Files         240      240              
  Lines       15016    14995      -21     
==========================================
+ Hits         7050     7060      +10     
+ Misses       7070     7037      -33     
- Partials      896      898       +2     

Impacted Files	Coverage Δ
pkg/apiclient/http1/event-watch-client.go	0.00% <0.00%> (ø)
...kg/apiclient/http1/cron-workflow-service-client.go	0.00% <0.00%> (ø)
...piclient/argo-kube-cron-workflow-service-client.go	0.00% <0.00%> (ø)
...lient/error-translating-workflow-service-client.go	0.00% <0.00%> (ø)
...ient/argo-kube-workflow-template-service-client.go	0.00% <0.00%> (ø)
.../error-translating-cron-workflow-service-client.go	0.00% <0.00%> (ø)
...o-kube-cluster-workflow-template-service-client.go	0.00% <0.00%> (ø)
cmd/argoexec/commands/emissary.go	50.00% <0.00%> (+1.56%)	⬆️
server/workflow/workflow_server.go	42.73% <0.00%> (+2.27%)	⬆️
pkg/apiclient/apiclient.go	14.28% <0.00%> (+8.73%)	⬆️

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[alexec]

Do we need this now with my fix?

[simster7]

Do we need this now with my fix?

I believe so, I will explain once I gather more information

[simster7]

Not needed