Rule proposal: template/no-restricted-syntax

[rafaelss95]

Similar to https://eslint.org/docs/rules/no-restricted-syntax, but for templates. Taking #308 as an example:

{
  "rules": {
    "@angular-eslint/template/no-restricted-syntax": [
      "error",
      {
        "selector": "Element[name='button']:not(:has(:matches(BoundAttribute, TextAttribute)[name='type']))",
        "message": "Missing an explicit type attribute for button"
      },
      {
        "selector": "Element[name='button'] :matches(BoundAttribute, TextAttribute)[name='type'][value!=/^(button|reset|submit)$/]",
        "message": "Invalid value for button type attribute"
      },
    ]
  }
}

[JamesHenry]

Nice idea, @rafaelss95! I think it would be a good addition