chore: add #[non_exhaustive] and mutation methods to improve compatibility (#715)

* chore: add #[non_exhaustive] to reduce backwards-incompatible changes going forward

* fix: remove ProtocolVersion import

* fix: add a few more with_ mutator methods

---------

Co-authored-by: Alex Hancock <alexhancock@block.xyz>

examples/servers/src/elicitation_stdio.rs

@@ -154,14 +154,11 @@ impl ElicitationServer {
 #[tool_handler]
 impl ServerHandler for ElicitationServer {
     fn get_info(&self) -> ServerInfo {
-        ServerInfo {
-            capabilities: ServerCapabilities::builder().enable_tools().build(),
-            server_info: Implementation::from_build_env(),
-            instructions: Some(
+        ServerInfo::new(ServerCapabilities::builder().enable_tools().build())
+            .with_server_info(Implementation::from_build_env())
+            .with_instructions(
                 "Simple server demonstrating elicitation for user name collection".to_string(),
-            ),
-            ..Default::default()
-        }
+            )
     }
 }