Introduces a new TerminalSettingsModel (TSM) project. This project is
responsible for (de)serializing and exposing Windows Terminal's settings
as WinRT objects.
## References
#885: TSM epic
#1564: Settings UI is dependent on this for data binding and settings access
#6904: TSM Spec
In the process of ripping out TSM from TerminalApp, a few other changes
were made to make this possible:
1. AppLogic's `ApplicationDisplayName` and `ApplicationVersion` was
moved to `CascadiaSettings`
- These are defined as static functions. They also no longer check if
`AppLogic::Current()` is nullptr.
2. `enum LaunchMode` was moved from TerminalApp to TSM
3. `AzureConnectionType` and `TelnetConnectionType` were moved from the
profile generators to their respective TerminalConnections
4. CascadiaSettings' `SettingsPath` and `DefaultSettingsPath` are
exposed as `hstring` instead of `std::filesystem::path`
5. `Command::ExpandCommands()` was exposed via the IDL
- This required some of the warnings to be saved to an `IVector`
instead of `std::vector`, among some other small changes.
6. The localization resources had to be split into two halves.
- Resource file linked in init.cpp. Verified at runtime thanks to the
StaticResourceLoader.
7. Added constructors to some `ActionArgs`
8. Utils.h/cpp were moved to `cascadia/inc`. `JsonKey()` was moved to
`JsonUtils`. Both TermApp and TSM need access to Utils.h/cpp.
A large amount of work includes moving to the new namespace
(`TerminalApp` --> `Microsoft::Terminal::Settings::Model`).
Fixing the tests had its own complications. Testing required us to split
up TSM into a DLL and LIB, similar to TermApp. Discussion on creating a
non-local test variant can be found in #7743.
Closes#885
