Make projects AOT compatible

[NikolaMilosavljevic]

Contributes to #9193

Summary of changes.

1. Enable AOT compatibility analyzers on all src/ projects

Each .csproj under src/ received:

<IsAotCompatible Condition="$([MSBuild]::GetTargetFrameworkIdentifier('$(TargetFramework)')) == '.NETCoreApp'">true</IsAotCompatible>

The condition restricts it to .NET Core TFMs, avoiding errors on netstandard2.0 / net472.

2. Replace reflection-based JSON serialization with source-generated contexts

Three new JsonSerializerContext files were added to eliminate AOT-unsafe JsonSerializer.Serialize(obj) calls:

New file	Serializable type
GlobalSettingsJsonSerializerContext.cs	GlobalSettingsData
SettingsStoreJsonSerializerContext.cs	SettingsStore
TemplateCacheJsonSerializerContext.cs	TemplateCache

The callers in GlobalSettings.cs, ComponentManager.cs, and TemplatePackageManager.cs were updated to use the new typed WriteObject<T> overload with JsonTypeInfo<T>.

3. Convert WriteObject to a type-safe generic

In JExtensions.cs, the untyped WriteObject(string, object) was replaced with:

WriteObject<T>(string path, T obj, JsonTypeInfo<T> jsonTypeInfo)

This uses JsonSerializer.Serialize(stream, obj, jsonTypeInfo) — fully AOT-safe.

4. Source-gen context for JsonEncodeValueFormFactory

In JsonEncodeValueFormFactory.cs, the static JsonSerializerOptions + JsonSerializer.Serialize(value, options) was replaced with a JsonEncodeSerializerContext using [JsonSerializable(typeof(string))], calling JsonSerializer.Serialize(value, context.String).

5. AOT suppression attributes on reflection-heavy methods

Methods that inherently use reflection (assembly loading, Type.GetType(), Activator.CreateInstance) received method-level [UnconditionalSuppressMessage] attributes with specific IL warning codes:

File	Methods annotated	Warning codes
ComponentManager.cs	Constructor, TryGetComponent<T>, RegisterType, GetType	IL2026, IL2057, IL2067, IL2070, IL2072, IL3000, IL3050
Scanner.cs	ScanForComponents, LoadAllFromPath	IL2026
ReflectionLoadProbingPath.cs	SelectBestMatch, Resolving	IL2026
Bootstrapper.cs	Register(Assembly)	IL2026

6. AOT annotations on remaining unsafe shared methods

ToJsonString(object) and FromObject(object) in JExtensions.cs received [RequiresUnreferencedCode] + [RequiresDynamicCode] attributes, propagating warnings to callers. The callers in TemplateSearchCache.Json.cs, TemplateSearchData.Json.cs, TemplatePackageSearchData.Json.cs, and TemplateDiscoveryMetadata.cs received corresponding [UnconditionalSuppressMessage] attributes with justifications.

All attributes are guarded with #if NET7_0_OR_GREATER (or #if NET where appropriate) so they compile cleanly on older TFMs.