reloadServer() sent the rust-analyzer-specific rust-analyzer/reloadWorkspace
request to every server before falling back to workspace/didChangeConfiguration.
Servers that crash on an unknown method instead of replying -32601 (Roslyn,
dotnet/roslyn#84890) were killed by `lsp reload` rather than reloaded.
Gate the request on isRustAnalyzerClient (exported from client.ts) or a
"rust-analyzer" server name; every other server reloads via
workspace/didChangeConfiguration directly. Consolidate tool.ts's inline
rust-analyzer detection onto the same helper.
Fixes#8571