RS: Added mtls_trusted_ca to the certificates table

[rrelledge]

DOC-1574

[github-actions]

Staging links:
https://redis.io/docs/staging/DOC-1574/operate/rs/security/certificates/

[dwdougherty]

LGTM.

[yoavredis]

@rrelledge a few comments:

1. If certain certificates are not auto-generated and are later uploaded (optionally) by the customer, then they most likely won't be "self-signed" certs. The whole point of "self-signed" certs is that the system generates them so that the customer won't have to supply its own.
2. Per Eng, ldap_client and mtls_trusted_ca are not auto-generated by the cluster. Thus, the opening paragraph is misleading the reader into thinking that the system auto-generates self-signed certificates for the entire list.

I suggest to:

• Add a 3rd column to the certificate list, indicating auto-generated yes/no
• Explain that the list contains all the supported certificates.
  -- Some are auto-generated (self-signed) to be used OOTB, and could be replaced with customer's certs
  -- Some are not auto-generated which makes them optional. They must be provided by the customer for using the specific feature they are coupled with.

[yoavredis]

@rrelledge now it's clear and accurate :)
LGTM, 10x.