[IMP] website,*: removes compatibility layer for (really) old browsers

*:web_editor,portal

This commit aims at removing the need to rely on `$.browser`, which was
mainly the case to support deprecated and unsupported browsers like MS
Internet Explorer or old version of Firefox.

Doing so, this commit removes the `data-browser` attribute initialy
introduced by odoo/odoo@a7e0b73930 as not
needed anymore nowadays and to generally promote "feature detection"
instead of "user-agent sniffing" to handle browsers' feature support and
edge cases.

task-3439226

Part-of: odoo/odoo#133916

addons/portal/static/src/js/portal_sidebar.js

@@ -50,12 +50,6 @@ var PortalSidebar = publicWidget.Widget.extend({
      * @param {string} href
      */
     _printIframeContent: function (href) {
-        // due to this issue : https://bugzilla.mozilla.org/show_bug.cgi?id=911444
-        // open a new window with pdf for print in Firefox (in other system: http://printjs.crabbly.com)
-        if ($.browser.mozilla) {
-            window.open(href, '_blank');
-            return;
-        }
         if (!this.printContent) {
             this.printContent = $('<iframe id="print_iframe_content" src="' + href + '" style="display:none"></iframe>');
             this.$el.append(this.printContent);

addons/web_editor/static/src/scss/web_editor.common.scss

@@ -280,10 +280,6 @@ div.media_iframe_video {
     }
 }
 
-html[data-browser^="msie"] div.media_iframe_video iframe {
-    margin-left: 0;
-}
-
 // Fields
 address {
     .fa.fa-mobile-phone {

addons/website/static/src/js/content/compatibility.js

@@ -5,19 +5,6 @@
  * content too.
  */
 
-// Check the browser and its version and add the info as an attribute of the
-// HTML element so that css selectors can match it
-var browser = Object.entries($.browser).map(([key, val]) => val === true && key)[0]
-if ($.browser.mozilla && +$.browser.version.replace(/^([0-9]+\.[0-9]+).*/, '\$1') < 20) {
-    browser = 'msie';
-}
-browser += (',' + $.browser.version);
-var mobileRegex = /android|webos|iphone|ipad|ipod|blackberry|iemobile|opera mini/i;
-if (mobileRegex.test(window.navigator.userAgent.toLowerCase())) {
-    browser += ',mobile';
-}
-document.documentElement.setAttribute('data-browser', browser);
-
 // Check if flex is supported and add the info as an attribute of the HTML
 // element so that css selectors can match it (only if not supported)
 var htmlStyle = document.documentElement.style;
@@ -29,6 +16,5 @@ if (!isFlexSupported) {
 }
 
 export default {
-    browser: browser,
     isFlexSupported: isFlexSupported,
 };