Add basic JSON and YAML rendering in pre tag

[cianmce]

Following on from idea: https://github.com/ankane/blazer/issues/388

If a column name contains JSON or YAML then do the appropriate parsing and pretty-printing, if parsing fails then just return the value in a pre tag and highlight using hljs

We could also add config to explicitly enable or disable this, similar to what is done with image

---

Sample SQL using MySQL data source

SELECT
  'test: {"k2": "v2", "k3": {"k4": "v4"}}\ntest2: [1,2]' AS sample_yaml,
  '{"test":{"k2":"v2","k3":{"k4":"v4"}},"test2":[1,2]}' AS sample_json,
  'test_content' AS sample_text
UNION
SELECT 'invaid: yaml\nobject', '{"invalid": "json"', 'more_text'

[jpaulomotta]

I think this is a great idea and it would be useful on projects that I'm working on.

[cianmce]

@ankane is this something you'd look at including?