When the `expand_icon` is switched, the size cache can be updated to
solve the issue that the cache cannot be updated when the `OptionButton`
is enabled with `fit_to_longest_item`.
Frame deltas are currently measured by querying the OS timer each frame. This is subject to random error. Frame delta smoothing instead filters the delta read from the OS by replacing it with the refresh rate delta wherever possible.
This PR also contains code to estimate the refresh rate based on the input deltas, without reading the refresh rate from the host OS.
The delta_smooth_enabled setting can also be modified at runtime through OS::, and there is also now a command line setting to override the project setting.
The `InputEvent` class currently supports the `pressed` and `released` states, which given the binary nature, is represented by a `bool` field.
This commit introduced the `CANCELED` state, which signals that an ongoing input event has been canceled.
To represent all the states, the `InputEventState` enum is added and the `InputEvent` logic is refactored accordingly.
This commit introduce separate types (e.g. GDNativeStringPtr vs GDNativeUninitializedStringPtr)
depending on if the pointed data is already initialized (C++ style where constructor is alway
called when create a variable even if it is to be passed as return value) or not (C style).
On top of that, small changes has been made to `GDNativeInterface` so that it methods are
consistent on using uninitialized return value.
This adds a way to ensure that methods that were modified in the Godot API will continue working in older builds of GDExtension even if the new signature is different.
```C++
// New version (changed)
ClassDB::bind_method(D_METHOD("add_sphere","radius","position"),&MyShapes::add_sphere);
// Compatibility version (still available to extensions).
ClassDB::bind_compatibility_method(D_METHOD("add_sphere","radius"),&MyShapes::_compat_add_sphere);
```
**Q**: If I add an extra argument and provide a default value (hence can still be called the same), do I still have to provide the compatibility version?
**A**: Yes, you must still provide a compatibility method. Most language bindings use the raw method pointer to do the call and process the default parameters in the binding language, hence if the actual method signature changes it will no longer work.
**Q**: If I removed a method, can I still bind a compatibility version even though the main method no longer exists?
**A**: Yes, for methods that were removed or renamed, compatibility versions can still be provided.
**Q**: Would it be possible to automate checking that methods were removed by mistake?
**A**: Yes, as part of a future PR, the idea is to add a a command line option to Godot that can be run like : `$ godot --test-api-compatibility older_api_dump.json`, which will also be integrated to the CI runs.
