Fixed following issues in ERD:

1) After opening an existing project, the first table is already selected but the edit, clone, delete buttons are disabled.
 2) ERD project title gets changed when 2 ERD projects are open & anyone of it edited.
 3) Closing the ERD tab does not ask for a confirmation pop-up.
 4) Shortcut for 'Show more/Fewer details' is missing.
 5) Deleting the primary key does not delete associated links.
 6) The long table & schema name are getting out of the box.
 7) The long table name in the notes pop-up needs re-alignment.
 8) The same table name present in ERD/canvas is allowed in Add Table dialogue. Added validation in the dialog.
 9) Download image option is added, but it is not perfect yet. Image icons (table, schema, etc.) are not showing up.
 10) Rename panel option should be disabled by default. It should be enabled for the tools which implement rename functionality.
 11) The Toolbar is not visible in Safari for the ERD tool.

refs #1802

web/pgadmin/tools/erd/__init__.py

@@ -288,6 +288,24 @@ class ERDModule(PgAdminModule):
             fields=shortcut_fields
         )
 
+        self.preference.register(
+            'keyboard_shortcuts',
+            'show_details',
+            gettext('Show more/fewer details'),
+            'keyboardshortcut',
+            {
+                'alt': True,
+                'shift': False,
+                'control': True,
+                'key': {
+                    'key_code': 84,
+                    'char': 't'
+                }
+            },
+            category_label=PREF_LABEL_KEYBOARD_SHORTCUTS,
+            fields=shortcut_fields
+        )
+
         self.preference.register(
             'keyboard_shortcuts',
             'zoom_to_fit',