Improve translation flexibility of ordinal template tag results

[Tzu-ping Chung]

There are languages, e.g. Chinese, that do not use suffix, but prefix to indicate ordinals. The current implementation means that it is impossible to translate the suffixes to work with those languages. I understand this has its root in a much larger issue (#15156), but this can be fixed very trivially by including the whole format instead of just the suffix, something like:

@register.filter(is_safe=True)
def ordinal(value):
    """
    Convert an integer to its ordinal as a string. 1 is '1st', 2 is '2nd',
    3 is '3rd', etc. Works for any integer.
    """
    try:
        value = int(value)
    except (TypeError, ValueError):
        return value
    formats = (_('%dth'), _('%dst'), _('%dnd'), _('%drd'), _('%dth'), _('%dth'), _('%dth'), _('%dth'), _('%dth'), _('%dth'))
    if value % 100 in (11, 12, 13):  # special case
        return mark_safe(formats[0] % (value,))
    return mark_safe(formats[value % 10] % (value,))

I can submit a pull request if this is considered reasonable.

[Claude Paroz]

Pull request welcome!

[Tzu-ping Chung]

​PR

[Tim Graham <timograham@…>]

In 85e6a1c6:

Fixed #28877 -- Made ordinal template filter results more localizable.

Marked the whole pattern (e.g. "{value}th") as translatable, instead of
just this suffix, so that languages not using suffixes for ordinals can
use this tag.

[nessita <124304+nessita@…>]

In 9adc205:

Refs #28877 -- Added special ordinal context when humanizing value 1.

Some languages use a different ordinal suffix for the number 1 than
for other values ending in 1 (e.g. 21, 31). Added a dedicated
pgettext context "ordinal is 1" to allow translators to handle
this distinction.

For example, in French, 1 is written as "1er" while 21, 31, etc. use
"21e", "31e", etc.

Co-authored-by: Natalia <124304+nessita@…>