Adapt chectl to fixes for TLS for helm chart

[sleshchenko]

What does this PR do?

TODO revise --chenamespace=chenamespace parameter

1. Fixes documentation since --tls does not enable multiuser anymore.
2. The only server strategy that works is multi-host and it requires wildcards certificates. It's why helm chart does not include cluster issuer and certificates anymore. User must provide che-tls secret with certificate content.
   It's why checking that cert-manager is set is removed, as well as propagating tls.email parameter.

It's tested on GCP with the following configurations:

./bin/run server:start -a=helm -p=k8s -b=che.gcps.my-ide.cloud --tls --multiuser

./bin/run server:start -a=helm -p=k8s -b=che.gcps.my-ide.cloud --tls

./bin/run server:start -a=helm -p=k8s -b=che.gcps.my-ide.cloud --multiuser

What issues does this PR fix or reference?

It's needed after eclipse-che/che#13946

[l0rd]

I am on PTO I won't able to test it today. Will be back on Monday but feel free to merge it if it gets approved before.

[benoitf]

FYI semantic commits and DCO checks are failing

[benoitf]

(see CONTRIBUTING.MD)

[benoitf]

tested on GCP