We were accidentally stopping the recursion when matching in the case sensitive scenario.
Took the opportunity to also rename the private method to follow the Core method naming more closely so it's easier to compare the implementations in the future.
Also, the private method now uses `ReadOnlySpan<char>` to avoid allocating strings on each recursion.
Instead of making the accessors `internal` which can break binary compat, make them `public` but hide them with EB never so they don't show up in IntelliSense.
Also, do the same for properties with the `PROPERTY_USAGE_INTERNAL` flag. These properties were not meant to be exposed to scripting, but since they've been public before all we can do now is hide them.
The Godot.NET.Sdk (for C# use) should define the property `UsingGodotNETSdk` in its [SDK.props](a07dd0d6a5/modules/mono/editor/Godot.NET.Sdk/Godot.NET.Sdk/Sdk/Sdk.props).
## Why
Defining this property allows shared build configuration (e.g. Directory.Build.targets or other imported msbuild files) to detect deterministically when they are operating within the scope of a project controlled by Godot.NET.Sdk. This enables shared build configuration that may span many different projects within a folder to have Godot.NET.Sdk-specific configuration that only applies to Godot projects.
## Why named UsingGodotNETSdk
This naming scheme is common practice in Microsoft Dotnet SDKs. For example, the property `UsingMicrosoftNETSdk` is defined by the default SDK, `UsingMicrosoftTraversalSdk` is defined by [Microsoft.Build.Traversal](363532de5b/src/Traversal/Sdk/Sdk.props (L10)), `UsingMicrosoftNoTargetsSdk` by [Microsoft.Build.NoTargets](363532de5b/src/NoTargets/Sdk/Sdk.props (L10)), and so on. The property `UsingMicrosoftNETSdk` is even used in the implementation of Godot.NET.Sdk for conditional logic of the type predicted here.
Note that these "Using*" properties are _additive_ in the sense that more than one can be defined for a given project (as SDKs can effectively be built upon other SDKs, using them as components). So, it is normal and appropriate for both `UsingMicrosoftNETSdk` and `UsingGodotNETSdk` to be simultaneously defined within the same project.
Defaults to "Auto", which detects the casing based on the
preference of the currently selected language (C# for example
prefers PascalCase whereas GDScript prefers snake_case).
