* Remove dead lazy code

* Remove `TRUELENGTH` backed character sort

Still need to properly support `NA`, `decreasing`, and `na_last`, but this is a major part of it

* Add `decreasing`, `na_last`, and `NA` support in `chr_order_insertion()`

* Handle `decreasing`, `na_last` and `NA` in `chr_order_radix()`

* Move the all-same-byte check before the histogram

* Get `order.Rmd` working again

* Consistency tweaks

* Recognize that we can pointer swap `p_x` and `p_x_aux`

* Split `struct str_info` into individual components (#2120)

* Split `struct str_info` into individual components

The `struct` forces an 8 byte alignment, so it costs us 24 bytes for this struct, when it should really only cost 20 bytes. Since we need 2 vectors of these, thats 8 wasted bytes per string that we can save by splitting them back up, at the cost of more bookkeeping.

* Track `NA`ness rather than whole `SEXP` (#2121)

* Track `NA`ness rather than whole `SEXP`

For 14 bytes less memory per string

* Go back to post check loading

* Handle `NA`s up front (#2122)

* Handle `NA`s up front

Avoiding the need for `p_x_string_nas_aux` altogether, and nicely simplifying and speeding up the radix and insertion paths

* Remove `p_lazy_x_string_nas` entirely

By having the `SEXP` be available in both `chr_order()` and `chr_order_chunk()`

* Split extraction and order rearrangement

* Simplify aux placement code

* Remove `x_string_sizes` as well (#2123)

* Remove size related vectors

* Advance `p_x[i]` in place, rather than accessing with `[pass]`

This keeps `p_x[i]` up to date after each pass, always pointing to the next byte.

This didn't seem to have much of a performance impact, but it nicely cleans up `chr_insertion_order()` and `chr_all_same_byte()` because they no longer need to worry about the `pass`, the pointers are always advanced to `pass` already

* Tweak comment

* Another empty string test

* Make the `\0` early exit less hidden