Rollup merge of #155527 - Jules-Bertholet:riir-printable, r=Mark-Simulacrum

Replace printables table with `unicode_data.rs` tables

This gets rid of the `printable.py` script, ensuring that `unicode-table-generator` handles all our Unicode data table generation needs.

There are also some drive-by documentation improvements in `library/core/char/methods.rs`.

There is one change in behavior: we now consider all characters with the `Default_Ignorable_Code_Point` property to be unprintable. These characters can be hidden/invisible otherwise.

I've chosen to give each Unicode property its own table, instead of merging them all into one. This is slightly less efficient in terms of space, but should allow us to expose these tables in the future with public methods on `char`.

@rustbot label A-Unicode