renameSymbol
Prompt the user for a new name for the symbol at the cursor and, on confirmation, ask the language server to rename it.
Ports upstream @codemirror/lsp-client's renameSymbol command:
resolves this editor's RenameServer binding from the renameServer facet; returns false (command not handled) when none is installed,
returns false when the cursor is not over a word (wordAt) or the server explicitly lacks
renameProvider,otherwise opens an input prompt prefilled with the current word (the RenameState tooltip). Confirming the prompt (confirmRename) flushes pending edits (LSPClient.sync), issues
textDocument/renameat the word start, and applies the resulting WorkspaceEdit.
Deviation from upstream: upstream optionally reuses an already-open dialog (getDialog) and reprefills it; kodemirror simply re-opens the prompt (the effect replaces any prior RenameState).
Return
true when the command is handled (a binding + word exist and the server advertises the capability), so the keymap stops here; false to fall through.