Fixes: #239
Fixes: #260

This has a lot of improvements related to generating the .d.ts and .js files for the .NET node module scenario, including ES and AOT.

• When generating typedefs for an assembly that includes [JSExport] attributes, export items directly from the module rather than augmenting the node-api-dotnet module. (The augmentation is only when dynamically loading pre-existing assemblies.)
• Use new template JS code for module-loader scripts that has correct export behavior for modules vs dynamically-loaded assemblies.
• In MSBuild targets, when publishing AOT, transform the generated module-loader scripts so they load the native binary directly.
• Add ability for the TS generator to produce both .cjs and .mjs loader scripts, or just one of them (as .js).
• Add ability for the TS generator to auto-detect the module system (CommonJS vs ES) based on the current project's package.json. This is the new default behavior, hooked up automatically in NodeApi.Generator.targets, and eliminates the need to specify the module type via an MSBuild property in the project most of the time.
• Improve support for ES default exports in the TS generator.
• Fix some issues in ModuleGenerator and TypeDefinitionsGenerator related to un-namespaced types. (Does not fully resolve Add full support for types/interfaces/delegates without namespaces #262.)
• Update the matrix of JS/TS + CommonJS/ESM dynamic-invoke project test cases to use the new capabilities, and add new parallel test cases for "module" projects.
• Switch some example projects to ES instead of CommonJS module system.
• Bump version to 0.7.

The overall effect of these changes is that the generated typedefs and loader scripts now work correctly and automatically in many scenarios where they were broken before or required some workarounds to consume.