chore: set extension kind as 'workspace'

Extension kind can also be UI, meaning that it can run anywhere, but
this extension works with file system and debugger, so it must run on
same machine where debugging occurs

Author: ashenBlade

package.json

@@ -11,6 +11,7 @@
         "Formatters",
         "Other"
     ],
+    "extensionKind": ["workspace"],
     "icon": "resources/logo.png",
     "activationEvents": [
         "workspaceContains:.vscode/pgsql_hacker_helper.json",