AppServerOrSAMLIdPServiceProvider type deprecation and backport plan for Connect

[flyinghermit]

The #38709 PR deprecates KindAppOrSAMLIdPServiceProvider and AppServerOrSAMLIdPServiceProvider types.

The Web UI and Connect will still show SAML resource as "apps", we are only deprecating the usage of AppServerOrSAMLIdPServiceProvider in favor of processing types.AppServer and types.SAMLIdPServiceProvider individually in the Auth Service.

However, this is a breaking change for Connect (when Auth Service runs in v16 but Connect is on v15 current master) as the teleterm package used in Connect does not handle the types.SAMLIdPServiceProvider type. Though the teleterm package is updated in the same PR to recognize the types.SAMLIdPServiceProvider type, we need a backport/deprecation plan for Connect so it does not break when v16 is released.

The PR proposes to selectively backport teleterm package to v15. Since the v15 is fairly new, we can expect users to have been updated to latest v15.x by the time v16 is released.

The other option is to update Auth Service in v16 to respond with types based on client version.

[flyinghermit]

FYI, @gzdunek, @zmb3