Add invokeAction method to the fixtures lib

[nizienko]

    fun RemoteRobot.invokeAction(actionId: String) {
        runJs(
                """
            const actionId = "$actionId";
            const actionManager = com.intellij.openapi.actionSystem.ActionManager.getInstance();
            const action = actionManager.getAction(actionId);
            actionManager.tryToExecute(action, com.intellij.openapi.ui.playback.commands.ActionCommand.getInputEvent(actionId), null, null, true);
        """, true
        )
    }