chore: generate countries.tsx from Go code (#15274)

Closes https://github.com/coder/coder/issues/15074

We have a hard-coded list of countries at
https://github.com/coder/coder/blob/main/site/src/pages/SetupPage/countries.tsx.
This means Go code in coder/coder doesn't have an easy way of utilizing
it.

## Solution
Generate countries.tsx from Go code. Generated by `scripts/apitypings`

scripts/typegen/typescript.tstmpl

@@ -0,0 +1,19 @@
+// Code generated by typegen/main.go. DO NOT EDIT.
+
+import type { RBACAction, RBACResource } from "./typesGenerated";
+
+// RBACResourceActions maps RBAC resources to their possible actions.
+// Descriptions are included to document the purpose of each action.
+// Source is in 'coderd/rbac/policy/policy.go'.
+export const RBACResourceActions: Partial<
+  Record<RBACResource, Partial<Record<RBACAction, string>>>
+> = {
+  {{- range $element := . }}
+    {{- if eq $element.Type "*" }}{{ continue }}{{ end }}
+  {{ $element.Type }}: {
+    {{- range $actionValue, $actionDescription := $element.Actions }}
+    {{ $actionValue }}: "{{ $actionDescription }}",
+    {{- end }}
+  },
+  {{- end }}
+};