fix: bootstrap styles are not available in BOS components

Author: alsakhaev

libs/engine/src/app/components/context-manager.tsx

@@ -192,7 +192,11 @@ const InsPointHandler: FC<{
     config.layoutManagers.ear === layoutManagerId ? { position: 'relative' } : undefined
 
   return (
-    <ShadowDomWrapper className="mweb-layout-manager" style={shadowDomHostStyles}>
+    <ShadowDomWrapper
+      className="mweb-layout-manager"
+      style={shadowDomHostStyles}
+      stylesheetSrc={engine.config.bosElementStyleSrc}
+    >
       <Widget
         src={layoutManagerId ?? config.layoutManagers.horizontal}
         props={props}

libs/engine/src/app/components/shadow-dom-wrapper.tsx

@@ -44,6 +44,11 @@ export const ShadowDomWrapper = React.forwardRef<HTMLDivElement, ShadowDomWrappe
             justify-content: center;
             /* position: relative; */
             visibility: visible !important;
+
+            font-family: -apple-system, BlinkMacSystemFont, 
+              "Segoe UI", "Roboto", "Oxygen", "Ubuntu", "Cantarell", 
+              "Fira Sans", "Droid Sans", "Helvetica Neue", 
+              sans-serif;
             }
         `
         const disableCssInheritanceStyle = document.createElement('style')