refactor: Multiple UI improvements;

Use FrameData struct to store commonly accessed data, in order to
reduce mutex locks.

rename unpause to resume

use get_selected_panel() function instead of directly
gui_state.selected_panel

debug mode now shows some usefull information

src/app_data/container_state.rs

@@ -28,6 +28,11 @@ impl ContainerId {
     pub fn get(&self) -> &str {
         self.0.as_str()
     }
+
+    /// Only return first 8 chars of id, is usually more than enough for uniqueness
+    pub fn get_short(&self) -> String {
+        self.0.chars().take(8).collect::<String>()
+    }
 }
 
 impl Ord for ContainerId {
@@ -443,6 +448,20 @@ pub struct ContainerItem {
     pub is_oxker: bool,
 }
 
+/// Basic display information, for when running in debug mode
+impl fmt::Display for ContainerItem {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        write!(
+            f,
+            "{}, {}, {}, {}",
+            self.id.get_short(),
+            self.name,
+            self.cpu_stats.back().unwrap_or(&CpuStats::new(0.0)),
+            self.mem_stats.back().unwrap_or(&ByteStats::new(0))
+        )
+    }
+}
+
 impl ContainerItem {
     /// Create a new container item
     pub fn new(