[EPIC] TUI Improvements

As we have so many great improvements and ideas on TUI it would be great to add an epic to track them all

- [x] #1797
- [x] #1787 (PR: https://github.com/apache/datafusion-ballista/pull/1808)
- [x] #1785
- [x] #1804
- [x] #1849
- [x] #1997

Ideas to be discussed

- [x] `t` binding to switch plan to tree
- [x] `m` binding to add plan metrics
- [x] update readme with `tui web` part
- [ ] create a blog post
- [ ] SSE job modifications (i.e. update the tui state with Server Side Events (push) instead of HTTP polls).
- [ ] deploy tui to a known url that we can trust, forward to and be publicly available

Start by reviewing the completed issue references and the remaining checklist in this epic, especially the blog post, SSE job updates, and public TUI deployment ideas. No source files, tests, or entry points are named, so each remaining idea should first be split into a scoped issue with its relevant implementation location and validation steps. Done means the selected item is implemented, documented where requested, and publicly available if deployment is chosen.

Written by the indexing model from the issue text.