Update keymap context binding behavior of > and ! (#34664)

Now ! means "no ancestors matches this", and > means "any descendent"
not "any child".

Updates #34570

Co-authored-by: Ben Kunkle <ben@zed.dev>

Release Notes:

- *Breaking change*. The context predicates in the keymap file now
handle ! and > differently. Before this change ! meant "this node does
not match", now it means "none of these nodes match". Before this change
> meant "child of", now it means "descendent of". We do not expect these
changes to break many keymaps, but they may cause subtle changes for
complex context queries.

---------

Co-authored-by: Ben Kunkle <ben@zed.dev>

assets/keymaps/vim.json

@@ -724,7 +724,7 @@
     }
   },
   {
-    "context": "AgentPanel || GitPanel || ProjectPanel || CollabPanel || OutlinePanel || ChatPanel || VimControl || EmptyPane || SharedScreen || MarkdownPreview || KeyContextView || DebugPanel",
+    "context": "VimControl || !Editor && !Terminal",
     "bindings": {
       // window related commands (ctrl-w X)
       "ctrl-w": null,
@@ -782,7 +782,7 @@
     }
   },
   {
-    "context": "ChangesList || EmptyPane || SharedScreen || MarkdownPreview || KeyContextView || Welcome",
+    "context": "!Editor && !Terminal",
     "bindings": {
       ":": "command_palette::Toggle",
       "g /": "pane::DeploySearch"