Add avoid_breaking_exported_api config option
changelog: Add `avoid_breaking_exported_api` config option for [`enum_variant_names`], [`large_types_passed_by_value`], [`trivially_copy_pass_by_ref`], [`unnecessary_wraps`], [`upper_case_acronyms`] and [`wrong_self_convention`].
changelog: Deprecates [`pub_enum_variant_names`] and [`wrong_pub_self_convention`] as the non-pub variants are now configurable.
changelog: Fix various false negatives for `pub` items that are not exported from the crate.
A couple changes to late passes in order to use `cx.access_levels.is_exported` rather than `item.vis.kind.is_pub`.
I'm not sure how to better document the config option or lints that are (not) affected (see comments in #6806). Suggestions are welcome. cc `@rust-lang/clippy`
I added `/clippy.toml` to use the config internally and `/tests/clippy.toml` to maintain a default config in ui tests.
Closes#6806Closes#4504