fix: ordinal_num returns '1.0st' for float 1.0 instead of '1st'

[gaoflow]

Bug

num2words(1.0, to='ordinal_num') returns '1.0st' instead of '1st'.
The same problem affects every language that implements to_ordinal_num.

>>> num2words(1.0, lang='en', to='ordinal_num')
'1.0st'   # wrong
>>> num2words(2.0, lang='de', to='ordinal_num')
'2.0.'    # wrong
>>> num2words(1.0, lang='fr', to='ordinal_num')
'1.0er'   # wrong

Root cause

verify_ordinal accepts floats that equal their integer value (1.0 == int(1.0)),
so non-integer floats are correctly rejected while integer-valued floats pass through.
However, every to_ordinal_num implementation then converts value to a string with
str(value) or "%s" % value, which for 1.0 yields "1.0", embedding the decimal
point in the result.

Fix

Cast integer-valued floats to int inside num2words() before dispatching to the
language converter, for to='ordinal' and to='ordinal_num'. This fixes all language
implementations in one place without touching every language module.

# Before (wrong)
num2words(1.0, lang='en', to='ordinal_num')  # '1.0st'
num2words(2.0, lang='en', to='ordinal_num')  # '2.0nd'
num2words(21.0, lang='de', to='ordinal_num')  # '21.0.'

# After (correct)
num2words(1.0, lang='en', to='ordinal_num')  # '1st'
num2words(2.0, lang='en', to='ordinal_num')  # '2nd'
num2words(21.0, lang='de', to='ordinal_num')  # '21.'

Non-integer floats (1.5) still raise TypeError as before.