fix(template-generator): fix xss problem in issue message
fix(template-generator): fix xss problem in issue message

- use `_.escape` for html escape instead of `formatSourceCode`
- escape issue message when rendering issues\
   e.g. rule 'vue/no-lone-template' produces
   message '`<template>` require directive.'

mportuga/eslint-detailed-reporter,mportuga/eslint-detailed-reporter