- add hex and octal parsers to the Curl_str_* family
- make curlx_strtoofft use these parsers
- remove all use of strtol() and strtoul() in library code
- generally use Curl_str_* more than strtoofft, for stricter parsing
- supports 64-bit universally, instead of 'long' which differs in size
between platforms
Extended the unit test 1664 to verify hex and octal parsing.
Closes#16336
Designed to aid converting off from sscanf parsers. sscanf is hard to
use right, easy to mess up and often makes for sloppy error checking.
The new parsers allow more exact and pedandic parsing.
This new set of functions should be possible to use (and extend) and
switch over other libcurl parser code to use going forward.
Adapts the following to use the new functions:
- altsvc.c
- hsts.c
- http_aws_sigv4.c
Bonus: fewer memory copies, fewer stack buffers.
Test: Unit test1664
Docs: docs/internals/STRPARSE.md
Closes#15692
