HexEditor: Add Value Inspector

This adds a value inspector window to the Hex Editor. This window shows
the data at the current cursor position (or selection start if a range
is selected) interpreted as a variety of data types.

Currently supported values include 8, 16, 32, and 64 bit signed and
unsigned values as well as float and double.

The inspector can operate in both little endian and big endian modes.
This is switched between by options in the View menu.

Userland/Applications/HexEditor/HexEditorWindow.gml

@@ -18,13 +18,29 @@
             name: "editor"
         }
 
-        @GUI::Widget {
-            name: "search_results_container"
+        @GUI::VerticalSplitter {
+            name: "side_panel_container"
             visible: false
-            layout: @GUI::VerticalBoxLayout {}
 
-            @GUI::TableView {
-                name: "search_results"
+            @GUI::Widget {
+                name: "search_results_container"
+                visible: false
+                layout: @GUI::VerticalBoxLayout {}
+
+                @GUI::TableView {
+                    name: "search_results"
+                }
+            }
+
+            @GUI::Widget {
+                name: "value_inspector_container"
+                visible: false
+                layout: @GUI::VerticalBoxLayout {}
+
+                @GUI::TableView {
+                    name: "value_inspector"
+                    activates_on_selection: true
+                }
             }
         }
     }