overlays: Fix dependency cycle between popover.js and overlays.js.

This is a Prep PR for #24426.

Removes direct dependency cycle between 'popover.js'
and overlays.js by creating popover.initialize method
called from 'ui_init.js' that calls
overlays.register_pre_open_hook(hide_all) and
overlays.register_pre_close_hook(hide_all).

Created a function call_hook that loop call all
registered hooks at the start of 'open_overlay' and
'close_overlay'.

web/src/overlays.js

@@ -3,18 +3,34 @@ import Micromodal from "micromodal";
 
 import * as blueslip from "./blueslip";
 import * as browser_history from "./browser_history";
-import * as popovers from "./popovers";
 
 let $active_overlay;
 let close_handler;
 let open_overlay_name;
 
+const pre_open_hooks = [];
+const pre_close_hooks = [];
+
 function reset_state() {
     $active_overlay = undefined;
     close_handler = undefined;
     open_overlay_name = undefined;
 }
 
+export function register_pre_open_hook(func) {
+    pre_open_hooks.push(func);
+}
+
+export function register_pre_close_hook(func) {
+    pre_close_hooks.push(func);
+}
+
+function call_hooks(func_list) {
+    for (const element of func_list) {
+        element();
+    }
+}
+
 export function is_active() {
     return Boolean(open_overlay_name);
 }
@@ -62,7 +78,7 @@ export function active_modal() {
 }
 
 export function open_overlay(opts) {
-    popovers.hide_all();
+    call_hooks(pre_open_hooks);
 
     if (!opts.name || !opts.$overlay || !opts.on_close) {
         blueslip.error("Programming error in open_overlay");
@@ -210,7 +226,7 @@ export function open_modal(selector, conf = {}) {
 }
 
 export function close_overlay(name) {
-    popovers.hide_all();
+    call_hooks(pre_close_hooks);
 
     if (name !== open_overlay_name) {
         blueslip.error("Trying to close " + name + " when " + open_overlay_name + " is open.");

web/src/popovers.js

@@ -56,6 +56,11 @@ let userlist_placement = "right";
 
 let list_of_popovers = [];
 
+export function initialize() {
+    overlays.register_pre_open_hook(hide_all);
+    overlays.register_pre_close_hook(hide_all);
+}
+
 export function clear_for_testing() {
     $current_message_info_popover_elem = undefined;
     $current_user_info_popover_elem = undefined;

web/src/ui_init.js

@@ -62,6 +62,7 @@ import * as people from "./people";
 import * as pm_conversations from "./pm_conversations";
 import * as pm_list from "./pm_list";
 import * as popover_menus from "./popover_menus";
+import * as popovers from "./popovers";
 import * as presence from "./presence";
 import * as realm_logo from "./realm_logo";
 import * as realm_playground from "./realm_playground";
@@ -578,6 +579,7 @@ export function initialize_everything() {
 
     i18n.initialize(i18n_params);
     tippyjs.initialize();
+    popovers.initialize();
     popover_menus.initialize();
 
     initialize_user_settings(user_settings_params);