BRANCH_TOOLS
The tools that take branch: those that only read, each a command that takes --branch (readBranch). One reads
another branch (another session's, say) as it is, from inside a session, without moving it.
export const BRANCH_TOOLS: ReadonlySet<string> = new Set([ "tcm_status", "tcm_find", "tcm_search", "tcm_view", "tcm_deps", "tcm_dependents", "tcm_docs", "tcm_todo", "tcm_history", "tcm_at", ])