js: Break cyclic dependency between `admin.js` and `settings.js`.

There was a direct dependency between `admin.js` and `settings.js` which
was due to the fact that we needed to call `build_page` of both modules
in each other's `launch` function.

This is solved by lifting those `build_page` calls up from both modules to
`hashchange.js` which is the module which calls the `launch` function
of both modules.

web/src/admin.js

@@ -231,8 +231,6 @@ export function build_page() {
 }
 
 export function launch(section) {
-    settings.build_page();
-    build_page();
     settings_sections.reset_sections();
 
     settings.open_settings_overlay();

web/src/hashchange.js

@@ -343,11 +343,15 @@ function do_hashchange_overlay(old_hash) {
     }
 
     if (base === "settings") {
+        settings.build_page();
+        admin.build_page();
         settings.launch(section);
         return;
     }
 
     if (base === "organization") {
+        settings.build_page();
+        admin.build_page();
         admin.launch(section);
         return;
     }

web/src/settings.js

@@ -5,7 +5,6 @@ import timezones from "../generated/timezones.json";
 import render_settings_overlay from "../templates/settings_overlay.hbs";
 import render_settings_tab from "../templates/settings_tab.hbs";
 
-import * as admin from "./admin";
 import * as blueslip from "./blueslip";
 import * as browser_history from "./browser_history";
 import {$t, $t_html} from "./i18n";
@@ -134,8 +133,6 @@ export function open_settings_overlay() {
 }
 
 export function launch(section) {
-    build_page();
-    admin.build_page();
     settings_sections.reset_sections();
 
     open_settings_overlay();

web/tests/hashchange.test.js

@@ -125,11 +125,13 @@ function test_helper({override, change_tab}) {
     }
 
     stub(admin, "launch");
+    stub(admin, "build_page");
     stub(drafts, "launch");
     stub(message_viewport, "stop_auto_scrolling");
     stub(narrow, "deactivate");
     stub(overlays, "close_for_hash_change");
     stub(settings, "launch");
+    stub(settings, "build_page");
     stub(stream_settings_ui, "launch");
     stub(ui_util, "blur_active_element");
     stub(ui_report, "error");
@@ -294,6 +296,8 @@ run_test("hash_interactions", ({override}) => {
     $window_stub.trigger("hashchange");
     helper.assert_events([
         [overlays, "close_for_hash_change"],
+        [settings, "build_page"],
+        [admin, "build_page"],
         [settings, "launch"],
     ]);
 
@@ -303,6 +307,8 @@ run_test("hash_interactions", ({override}) => {
     $window_stub.trigger("hashchange");
     helper.assert_events([
         [overlays, "close_for_hash_change"],
+        [settings, "build_page"],
+        [admin, "build_page"],
         [admin, "launch"],
     ]);