Improve usability of keyring vs. keystore creation and configuration

[Joe-Winchester]

Customer content

Is your feature request related to a problem? Please describe.
Creating keyring vs. usskeystore involves modifying a single file zowe-create-certificates.env that contains overloaded parameters. This requires detailed doc and is error prone if mistakes are made or steps overlooked

Describe the solution you'd like

1. Revert zowe-setup-certificates.env to remove all mention of keyrings.
2. Create zowe-setup-keyring-certificates.env which has all of the keyring parms. KEYSTORE_ALIAS renamed to ZOWE_CERTIFICATE_LABEL.

User story now becomes:

zowe-setup-certificates.sh -p zowe-setup-uss-certificates.env' and 'zowe-setup-certificates.sh -p zowe-setup-keyring-certificates.env' Consider -gopt on the shell script instead ofGENERATE_CERTS_FOR_KEYRING=true`

Update the docs.

Consider Refactoring the zowe-setup-certificate.sh into two scripts to ensure the codepaths for keystore vs. keyring are not overloaded in the same script