I can't get the new feed counts

[lemon24]

Needed for the reader update progress bar; https://github.com/lemon24/reader/issues/204#issuecomment-780541740.

Types look as follows:

# for symmetry
def get_feeds(..., new: Optional[bool] = None)
def get_feed_counts(..., new: Optional[bool] = None)

# convenience property
class Feed:
    ...
    new: bool

# for compatibility, we'll have to keep also new_only around until 2.0;
# we should also make the arguments kw-only then
# def update_feeds(..., new_only: bool = False)
def update_feeds(..., new: Optional[bool] = None)
def update_feeds_iter(..., new: Optional[bool] = None)

[lemon24]

Related:

• 219 Can't filter by feed when updating feeds

• 220 Can't filter by update_enabled when updating feeds

• https://github.com/lemon24/reader/issues/241#issuecomment-856861768 filter by tag in update feeds

A theme emerges: It's useful to updates feeds filtered by whatever we can get/count them, and the other way around.