Upgrading from 4.x to 5.x

See v5 Release · Pull Request #982.

Most of the removed code was marked as obsolete for a long time in v4 before removed in v5 with details on what to replace the usage with.

💥 Breaking changes

1. Localization is based on CultureInfo.CurrentCulture instead of CurrentUICulture (#795, #986)
2. IQuantity returns QuantityValue instead of double (#1074)
3. Decimal based quantities return decimal instead of double (Power, BitRate and Information) (#1074)

🔥 Removed

1. Remove targets: net40, net47, Windows Runtime Component. Fix: Use netstandard2.0.
2. Remove Undefined enum value for all unit enum types. Fix: Use null.
3. Remove QuantityType enum. Fix: Use strings.
4. Remove IQuantity.Units and .UnitNames. Fix: Use QuantityInfo.
5. Remove IEquatable and equality operators/methods. Fix: See TODO below.
6. Remove GlobalConfiguration. Fix: Change CultureInfo.CurrentCulture.
7. Remove Molarity ctor and operator overloads. Fix: Use MassConcentration.FromMolarity(), ToMolarity().
8. Remove MinValue, MaxValue per quantity due to ambiguity. Fix: Define your own min/max quantity values.
9. Remove string format specifiers: "v", "s". Fix: Use Value property and standard .NET numeric format strings.
10. json: Remove UnitsNetJsonConverter. Fix: Use UnitsNetIQuantityJsonConverter or AbbreviatedUnitsConverter.

✨ New

1. QuantityValue: Implement IEquality, IComparable, IFormattable
2. QuantityValue: 16 bytes instead of 40 bytes (#1084)
3. Add [DataContract] annotations (#972)

📝 JSON unit definition schema changes

Rename BaseType to ValueType, for values "double" and "decimal". Rename XmlDoc to XmlDocSummary.

TODO

Add back IEquatable<T>, but implement as strict equality with tuple of quantity name + unit + value. https://github.com/angularsen/UnitsNet/issues/1017#issuecomment-1028401955