2.0 cleanup list

[robertbastian]

• [x] Unreadable inversion list JSON deserialization (#2855)
• [x] Remove support for legacy collator naming (sv_reformed_meta.toml)
• [x] Remove any.rs from databake provider generated code
• [x] Remove the definition of BakedDataProvider, instead favoring direct invocation of the macros (may need discussion)
• [x] Remove icu_datagen/legacy_api
  • [x] Remove extra segmenter data from icu_datagen (#3003)
• [x] CPT::get_ranges_for_value should be iter_ranges_for_value
• [x] TrieValue::to_u32() should not be default-impl'd
• [x] make properties set/map/script/etc from_data private or hidden
• [ ] Remove the icu_datetime_experimental feature from the icu metacrate (#3094)
• [ ] https://github.com/unicode-org/icu4x/issues/3573
• [ ] DateTimeFormat symbols data:
  • [ ] https://github.com/unicode-org/icu4x/issues/3599
  • [ ] https://github.com/unicode-org/icu4x/issues/3598
  • [ ] Should also consider splitting along symbol type
• [ ] calendar year/month methods:
  • [ ] Methods for getting formattable month/year should be called as such
  • [x] FormattableYear should use NonZeroU8 for cyclic
  • [ ] FormattableMonth should consider dropping ordinal or using something else.
• [ ] Japanese's try_new_date/time() should have a _with_calendar() and another baked version should be added that doesn't need the calendar parameter.
• [x] Find any #[deprecated] functions and remove them
• [ ] Remove mutable method on Ethiopic, potentially split calendar types
• [ ] Make capi baked data constructors the "normal" ones
• [x] Upgrade to regex automata 0.3 (https://github.com/unicode-org/icu4x/pull/3655)
• [x] RangeBounds references: https://github.com/unicode-org/icu4x/issues/3678
• [ ] Make icu4x-datagen CLI --fallback default to Auto
• [ ] FFI
  • [ ] Move everything to HIR
  • [ ] Move everything to renamed namespaced APIs
  • [ ] https://github.com/unicode-org/icu4x/issues/3791
  • [ ] #3851
• [x] Encapsulate DataKeyMetadata::{fallback_priority, extension_key, fallback_supplement} in a DataKeyMetadata::fallback_config
• [ ] Consider making AbstractSerializer not use trait objects for the FsExporter in datagen
• [ ] Fix name of DateTimeError::UnsupportedField
• [ ] Remove variants of DateTimeError that are unused, such as Format
• [ ] Stop exporting icu_datetime::CldrCalendar or mark it as "not intended to be implemented"
• [x] Delete strict_cmp_iter and SubtagOrderingResult in icu_locid (and any other deprecated APIs)

[Manishearth]

Properties cleanups:

We should remove all of the free functions:

• Binary property functions should go on CodePointSetData or whatever
• Enumerated property functions should live on the relevant property