obsfate: refactor obsfate data computing Refactor how obsfate data are computed in order to reuse this logic later when hooking on default log output.

topic: exclude public and topic changeset from branch stack Stack use-case is to show the current work in progress, which are symbolized by the phase draft and secret phase. Moreover showing public changesets in stack output when displaying current branch would display a lot of changesets for long-lived branches and would be quite useless. We also exclude topic changeset form the stack since they already exist on their own stack. getstack revsets didn't needed update when displaying a topic as when a changeset become public, its topic is no longer relevant.

tests: use a more portable form for new lines

topic: don't abort if there is no current topic in stack() revset Named branches support has been added and we should not abort if there is no active topic.