Remove Serialize/Deserialize functions never used in StandardCalculatorViewModel, UnitConverter and UnitConverterViewModel

[rudyhuyn]

Describe the change requested

StandardCalculatorViewModel as well as UnitConverterViewModel and UnitConverter contain custom binary serializers and deserializers never used by the application. I suspect they were used a long time ago when the app lifecycle model was more restricted (Windows Phone 8/8.1?).

These unused functions make it harder to add features or refactor these 3 classes, especially due to the format used (custom binary serialization).

A big part of the information saved by UnitConverter for example is not relevant or is redundant:

• CurrentCategory is already saved in LocalSettings by MainPage
• FromType and ToType are already saved by the function UnitConverter::SaveUserPreferences (in file) as well as by UnitConverterViewModel::SaveUserPreferences() (in LocalSettings)
• ratioMapTokens is based on static data (for unit conversion) or data already backed up by CurrencyDataLoader

Prerequisite
Be sure Microsoft doesn't use these functions in tools or code not in the git repository (integration tests, tools used by QA, etc..)

Functions no longer used we can remove

• CalculatorManager::SerializeCommands
• CalculatorManager::DeSerializeCommands
• UnitConverter::StringToCategory
• UnitConverter::StringToConversionData
• UnitConverter::ConversionDataToString
• UnitConverter::Serialize
• UnitConverter::DeSerialize
• StandardCalculatorViewModel::Serialize
• StandardCalculatorViewModel::Deserialize
• UnitConverterViewModel::Serialize
• UnitConverterViewModel::Deserialize

[MicrosoftIssueBot]

This is your friendly Microsoft Issue Bot. I've seen this issue come in and have gone to tell a human about it.