Rewrite pad_sort_key to account for alphanumeric pads.

[sabogalc]

This PR rewrites the pad_sort_key function to account for pad names such as A0 found on BGA packages. Below is a before and after with U30 on Glasgow. Previously, the pads were ordered
A1, A10, A11, A2, A3....
but now they are in the proper order.

[whitequark]

I think this will just as well, without hardcoding numbers:

Suggested change

	alphanumeric_parts = [f"{int(text):09d}" if text.isdigit() else text for text in parts if text]
	alphanumeric_parts = [text[::-1] if text.isdigit() else text for text in parts if text]

(It reverses the digit order by using a weird bit of Python syntax. It's basically str(reversed(text)) but in one operation.)

[sabogalc]

I just tested it and it still works great!

[sabogalc]

I apologize, I forgot to hit "Refresh Plugins", so even though I put your code into my plugins path, I was still running the previous code. Your solution results in this.

[sabogalc]

I think I may need to open a new PR but I will wait on confirmation from you to see if this can be reopened on your end.

I apologize for all of the disorder caused by my PRs.

[whitequark]

No this PR cannot be reopened since it was merged.

I will encourage you to learn how to use Git.

[sabogalc]

I agree, I'm very sorry for the mix-up. I'm much better at hardware than I am software. I will make a new PR for this just so that you don't have to be reliant on the .obdata one to fix this issue.

[whitequark]

Also yeah there's a logic error, I think this should actually work:

import re # at the beginning of file

def natural_sort_key(s):
    return [int(text) if text.isdigit() else text.casefold()
            for text in re.compile('([0-9]+)').split(s)]