Capitalized words are not inflected

Found a strange issue when trying to retrieve the plural of property, using either plural() or plural_noun():
```
Python 3.11.5 (tags/v3.11.5:cce6ba9, Aug 24 2023, 14:38:34) [MSC v.1936 64 bit (AMD64)] on win32

>>> import inflect
>>> p = inflect.engine()

>>> p.plural('property')
'properties'

>>> p.plural('Property')
'Propertys'
```
I looked through the documentation, but didn't see any notes about why this would be.

I think the plural of property, whether capitalized or not, should be properties.

Start by reproducing the reported behavior with plural() and plural_noun() using both "property" and "Property". Trace the inflection path for capitalization handling; the issue is done when the capitalized form produces the expected plural "properties" consistently with the lowercase form.

Written by the indexing model from the issue text.