File Explorer: Adds node context to file explorer item (#202)

* Adds an inline context item for refresh
* Adds "change root directory"
* Adds "change SSH username"

![image](https://github.com/tailscale-dev/vscode-tailscale/assets/40265/195db5a2-440d-4bcc-a423-714728c59d1f)

Signed-off-by: Tyler Smalley <tyler@tailscale.com>
(cherry picked from commit f005dd7)

package.json

@@ -148,17 +148,22 @@
         {
           "command": "tailscale.node.openTerminal",
           "when": "view == node-explorer-view && (viewItem =~ /^peer-file-explorer-dir/ || viewItem == peer-root)",
-          "group": "inline"
+          "group": "inline@1"
         },
         {
-          "command": "tailscale.node.openTerminal",
+          "command": "tailscale.node.openRemoteCode",
           "when": "view == node-explorer-view && (viewItem =~ /^peer-file-explorer-dir/ || viewItem == peer-root)",
-          "group": "1_action@1"
+          "group": "inline@2"
         },
         {
-          "command": "tailscale.node.openRemoteCode",
+          "command": "tailscale.nodeExplorer.refresh",
+          "when": "(view == node-explorer-view && viewItem == peer-root) || (view == node-explorer-view && viewItem == peer-file-explorer-dir-root)",
+          "group": "inline@3"
+        },
+        {
+          "command": "tailscale.node.openTerminal",
           "when": "view == node-explorer-view && (viewItem =~ /^peer-file-explorer-dir/ || viewItem == peer-root)",
-          "group": "inline"
+          "group": "1_action@1"
         },
         {
           "command": "tailscale.node.openRemoteCode",
@@ -167,24 +172,19 @@
         },
         {
           "command": "tailscale.node.setUsername",
-          "when": "view == node-explorer-view && viewItem == peer-root",
+          "when": "(view == node-explorer-view && viewItem == peer-root) || (view == node-explorer-view && viewItem == peer-file-explorer-dir-root)",
           "group": "2_settings@3"
         },
         {
           "command": "tailscale.node.setRootDir",
-          "when": "(view == node-explorer-view && viewItem == peer-root) || (view == node-explorer-view && viewItem =~ /^peer-file-explorer-root/)",
+          "when": "(view == node-explorer-view && viewItem == peer-root) || (view == node-explorer-view && viewItem == peer-file-explorer-dir-root)",
           "group": "2_settings@3"
         },
         {
           "command": "tailscale.node.copyIPv4",
           "when": "view == node-explorer-view && viewItem == peer-root",
           "group": "3_copy@1"
         },
-        {
-          "command": "tailscale.nodeExplorer.refresh",
-          "group": "inline",
-          "when": "view == node-explorer-view && viewItem =~ /^peer-file-explorer-root/"
-        },
         {
           "command": "tailscale.node.copyIPv6",
           "when": "view == node-explorer-view && viewItem == peer-root",