Split reflection-based JniTypeManager behavior

[simonrozsival]

Draft PR to let CI validate the JniTypeManager split and AOT warning work.

Summary:

• Keep JniTypeManager as the abstract base and move reflection-backed behavior into DynamicJniTypeManager.
• Update JRE/test managers that extend the default behavior to inherit from DynamicJniTypeManager.
• Keep NativeAOT sample managers on the abstract base with explicit mappings instead of reflection-backed base calls.
• Update public API baselines for the split.

Local validation:

• dotnet build src/Java.Interop/Java.Interop.csproj -p:JavaCPath="$JAVA_HOME/bin/javac" -p:JarPath="$JAVA_HOME/bin/jar"
• dotnet build tests/Java.Interop-Tests/Java.Interop-Tests.csproj -p:JavaCPath="$JAVA_HOME/bin/javac" -p:JarPath="$JAVA_HOME/bin/jar" -p:NativeToolchainSupported=false

Notes:

• Full local prepare/build is still blocked in this workspace by local build setup/toolchain issues, so this is intentionally draft for CI coverage.

[simonrozsival]

/azp run

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