To make the source code match the functions called at runtime.
And to avoid the preprocessor trick that may introduces build issues.
Before this patch, libtests, tunits and units were calling a mixture
of curl and system printf calls, then transformed them all to curl
printf calls by including `curl_printf.h`.
Changes made:
- tests: stop including `curl_printf.h`.
- libtest: switch a couple of outlier system printf calls to curl
printf.
- unit: use more curl printf to avoid casts and show whole values.
- unit: switch remaining calls to curl printf explicitly.
- tunit: switch to call curl printf explicitly.
- libtest, tunit, unit: ban system printf.
- unit1307, unit1607, unit1609, unit1652, unit1655, unit3214: bump
types/masks to avoid casts.
After this patch:
- libtests, tunits, units: use exclusively curl printf.
(as before, but explicitly, without relying on redefinitions.)
- servers: is unchanged (it can only use system printf).
Closes#18814
