Rename settings and keymap actions (#39970)

This PR renames the following actions to make it easier and prioritize
the UI version of interacting with them:

| Before | After |
|--------|--------|
| `OpenSettingsEditor` | `OpenSettings` |
| `OpenSettings` | `OpenSettingsFile` |
| `OpenKeymapEditor` | `OpenKeymap` |
| `OpenKeymap` | `OpenKeymapFile` | 

Release Notes:

- Rename actions to open settings (UI/window and JSON file) as well as
to open the keymap (editor tab and JSON file).

assets/keymaps/default-linux.json

@@ -30,8 +30,8 @@
       "ctrl-+": ["zed::IncreaseBufferFontSize", { "persist": false }],
       "ctrl--": ["zed::DecreaseBufferFontSize", { "persist": false }],
       "ctrl-0": ["zed::ResetBufferFontSize", { "persist": false }],
-      "ctrl-,": "zed::OpenSettingsEditor",
-      "ctrl-alt-,": "zed::OpenSettings",
+      "ctrl-,": "zed::OpenSettings",
+      "ctrl-alt-,": "zed::OpenSettingsFile",
       "ctrl-q": "zed::Quit",
       "f4": "debugger::Start",
       "shift-f5": "debugger::Stop",
@@ -621,7 +621,7 @@
       "ctrl-shift-f": "pane::DeploySearch",
       "ctrl-shift-h": ["pane::DeploySearch", { "replace_enabled": true }],
       "ctrl-shift-t": "pane::ReopenClosedItem",
-      "ctrl-k ctrl-s": "zed::OpenKeymapEditor",
+      "ctrl-k ctrl-s": "zed::OpenKeymap",
       "ctrl-k ctrl-t": "theme_selector::Toggle",
       "ctrl-alt-super-p": "settings_profile_selector::Toggle",
       "ctrl-t": "project_symbols::Toggle",