feat: generate TLS certificates using cert-manager

[luiscosta18]

What was changed
Add certificates.yaml + secret.yaml to templates

Why?
generate certificates using cert-manager

How was this tested
Deployed cert-manager helm-chart
Deployed temporal helm chart, 0.57.0, using temporal/charts/temporal/tests/certificates.yaml as values.yaml, with my own tls.crt + tls.key
Cert-manager will:

Use the temporal-issuer (which refers to the CA).
Ask the CA (from the tls-certs secret) to sign a new certificate.
Create the temporal-tls-certs secret in the same namespace — this secret will contain:
tls.crt: the signed certificate
tls.key: the private key
Optionally, ca.crt: the CA certificate (if configured)
➜ ~ kubectl get secret -n temporal

NAME TYPE DATA AGE
temporal-tls-certs kubernetes.io/tls 3 3h38m
tls-certs Opaque 2 153m

➜ ~ kubectl get certificate -n temporal

NAME READY SECRET AGE
temporal-cert True temporal-tls-certs 5h35m

➜ ~ kubectl get certificaterequests -n temporal-data

NAME APPROVED DENIED READY ISSUER REQUESTER AGE
temporal-cert-1 True True temporal-issuer system:serviceaccount:cert-manager:test-cert-manager 5h

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[luiscosta18]

Hello @robholland @tomwheeler @PhillypHenning

Please review this PR. Thanks.