agent: Improve the UX around interacting with MCP servers (#32622)

Still a work in progress! Todos before merging:

- [x] Allow to delete (not just turn off) an MCP server from the panel's
settings view
- [x] Also uninstall the extension upon deleting the server (check if
the extension just provides MCPs)
- [x] Resolve repository URL again
- [x] Add a button to open the configuration modal from the panel's
settings view
- [x] Improve modal UX to install and configure a non-extension MCP

Release Notes:

- N/A

---------

Co-authored-by: Bennet Bo Fenner <bennetbo@gmx.de>
Co-authored-by: Ben Brandt <benjamin.j.brandt@gmail.com>

crates/project/src/context_server_store.rs

@@ -235,6 +235,13 @@ impl ContextServerStore {
         self.servers.get(id).map(ContextServerStatus::from_state)
     }
 
+    pub fn configuration_for_server(
+        &self,
+        id: &ContextServerId,
+    ) -> Option<Arc<ContextServerConfiguration>> {
+        self.servers.get(id).map(|state| state.configuration())
+    }
+
     pub fn all_server_ids(&self) -> Vec<ContextServerId> {
         self.servers.keys().cloned().collect()
     }