Allow something to be Sensitive but also passable as plaintext

[Breee]

I have the case that i have properties in my upjet generated provider that i would like to be passable as secret but also as plaintext.

For example. currently we have this

    p.AddResourceConfigurator("keycloak_oidc_identity_provider", func(r *config.Resource) {
             
        // Mark fields as sensitive
        if s, ok := r.TerraformResource.Schema["client_id"]; ok {
            s.Sensitive = true
        }
        if s, ok := r.TerraformResource.Schema["client_secret"]; ok {
            s.Sensitive = true
        }
    })

This will require everyone to pass clientID and clientSecret as a secret.
I would like boolean property that allows me to have both. SecretRefs and Plaintext.

something like:

    p.AddResourceConfigurator("keycloak_oidc_identity_provider", func(r *config.Resource) {
++      r.Sensitive.AllowPlainTextValue = true
        // Mark fields as sensitive
        if s, ok := r.TerraformResource.Schema["client_id"]; ok {
            s.Sensitive = true
        }
        if s, ok := r.TerraformResource.Schema["client_secret"]; ok {
            s.Sensitive = true
        }
    })

what do you think?