Problem: the is_hidden_file and is_always_hidden config callbacks
only received (name, bufnr), making it impossible to filter by entry
type, permissions, or other metadata without reimplementing entry
lookup.
Solution: pass the full oil.Entry as a third argument to both
callbacks. Existing configs that only accept (name, bufnr) are
unaffected since Lua silently ignores extra arguments. The internal
should_display function signature changes from (name, bufnr) to
(bufnr, entry) to reflect its new contract.
Cherry-picked from: stevearc/oil.nvim#644