feat: add Icons plugin

* Change existing icons to React wrapper components

* Add `icons` plugin to expose Icon components to plugin system

* Create components that re-export Lock and Unlock components so they can be changed separately in Authorise top button and Authorise operation summary button

* Add new Lock and Unlock icons to `auth` plugin

---------

Co-authored-by: Vladimír Gorej <vladimir.gorej@smartbear.com>

src/core/components/auth/authorize-btn.jsx

@@ -14,14 +14,14 @@ export default class AuthorizeBtn extends React.Component {
 
     //must be moved out of button component
     const AuthorizationPopup = getComponent("authorizationPopup", true)
+    const LockAuthIcon = getComponent("LockAuthIcon", true)
+    const UnlockAuthIcon = getComponent("UnlockAuthIcon", true)
 
     return (
       <div className="auth-wrapper">
         <button className={isAuthorized ? "btn authorize locked" : "btn authorize unlocked"} onClick={onClick}>
           <span>Authorize</span>
-          <svg width="20" height="20">
-            <use href={ isAuthorized ? "#locked" : "#unlocked" } xlinkHref={ isAuthorized ? "#locked" : "#unlocked" } />
-          </svg>
+          {isAuthorized ? <LockAuthIcon /> : <UnlockAuthIcon />}
         </button>
       { showPopup && <AuthorizationPopup /> }
       </div>