Fixes many not yet enabled lints (mostly pedantic) on everything that is
not the lib (examples, benchs, tests). Therefore, this is not containing
anything that can be a breaking change.
Lints are not enabled as that should be the job of #974. I created this
as a separate PR as its mostly independent and would only clutter up the
diff of #974 even more.
Also see
https://github.com/ratatui-org/ratatui/pull/974#discussion_r1506458743
---------
Co-authored-by: Josh McKinney <joshka@users.noreply.github.com>
```shell
cargo run --example demo2 --features="crossterm widget-calendar"
```
Press `d` to activate destroy mode and Enjoy!

Vendors a copy of tui-big-text to allow us to use it in the demo.