Add AZC0034 C# type-name conflict linter

[haiyuazhang]

Parent: #4442
Draft implementation PR: #4910

Summary

Add a TypeSpec linter rule for AZC0034-style .NET SDK type-name conflicts. The rule should detect generated C# type names that conflict with reserved Azure SDK type names and offer a deterministic @@clientName(..., "csharp") fix.

Scope

• Use the Azure SDK analyzer reserved-name catalog as the source of truth.
• Detect generated C# model, enum, and union names.
• Suggest a service/namespace-prefixed C# name, for example Operation -> BillingOperation.
• Add the generated catalog, refresh script, tests, docs, and ruleset registration.

Acceptance criteria

• The rule reports diagnostics for generated C# model/enum/union names found in the AZC0034 reserved-name catalog.
• The code fix adds a C# @@clientName override in client.tsp.
• The catalog can be regenerated from the upstream Azure SDK analyzer files.
• The rule is enabled through the appropriate TCGC C# / client SDK ruleset path.