REF/BUG/ENH/API: refactor read_html to use TextParser

closes #4697 (refactor issue) (REF/ENH)
closes #4700 (header inconsistency issue) (API)
closes #5029 (comma issue, added this data set, ordering issue) (BUG)
closes #5048 (header type conversion issue) (BUG)
closes #5066 (index_col issue) (BUG)

- [x] figure out `skiprows`, `header`, and `index_col` interaction (a somewhat longstanding `MultiIndex` sorting issue, I just took the long way to get there :))
- ~~spam url not working anymore~~ (US gov "shutdown" is responsible for this, it correctly skips)
- ~~table ordering doc blurb/HTML gotchas~~ (was an actual "bug", now fixed in this PR)
- ~~add tests for rows with a different length~~ (this is already done by the existing tests)