Analyzer for reused serializer alias

[cbgrasshopper]

If a developer mistakenly reuses an Orleans serializer alias, Orleans produces a runtime error like this (type and alias names are represented with <PLACEHOLDER>s):

Unhandled exception. System.ArgumentException: An item with the same key has already been added. Key: <REUSED_ALIAS>
[04/11/2025 07:50:04 > 01f451: ERR ]    at System.Collections.Generic.Dictionary`2.TryInsert(TKey key, TValue value, InsertionBehavior behavior)
[04/11/2025 07:50:04 > 01f451: ERR ]    at System.Collections.Generic.Dictionary`2.Add(TKey key, TValue value)
[04/11/2025 07:50:04 > 01f451: ERR ]    at OrleansCodeGen.<TYPE_NAME>.Metadata_<TYPE_NAME>.ConfigureInner(TypeManifestOptions config) in <BUILD_OUTPUT_PATH>\Orleans.CodeGenerator\Orleans.CodeGenerator.OrleansSerializationSourceGenerator\<TYPE_NAME>.orleans.g.cs:line 32828
[04/11/2025 07:50:04 > 01f451: ERR ]    at Orleans.Serialization.Configuration.TypeManifestProviderBase.Microsoft.Extensions.Options.IConfigureOptions<Orleans.Serialization.Configuration.TypeManifestOptions>.Configure(TypeManifestOptions options) in /_/src/Orleans.Serialization/Configuration/ITypeManifestProvider.cs:line 22

Suggestion: Add an analyzer to produce an error at build time if a serializer alias is reused rather than only at runtime