Update `spfx project azuredevops pipeline add` and `spfx project github workflow add` commands to add support for federated Identity

Currently the m365 spfx project azuredevops pipeline add and m365 spfx project github workflow add commands will scaffold a yaml pipeline/workflow that defaults (or rather suggests) using certificate authentication method.
When the loginMethod option is set to application, which is the default value, the scaffolded yaml will have variable placeholders for specifying the certificate (either file or base 64 encoded string) and other properties like password etc.
What we could do is introduce a new possibility for the loginMethod option that use federated Identity login in the scaffolded flows and then for v11 we should consider this to make default option.

Currently, the -l, --loginMethod [loginMethod] option allows to be set as either user or application (default).
The naming here is not that best but what if we introduce a third option federatedIdentity and in future for v11 we rename the applciation to certificate to more align with options from the m365 login command?

Start with the two linked command documents and trace how the loginMethod option is handled for the Azure DevOps pipeline and GitHub workflow scaffolds. Compare the generated YAML for the existing user and application modes; the work is done when both commands support federatedIdentity consistently.