toolkit: Add list-topics command

[brian-kubisiak-skydio]

The list-topics command lists the topics for the current branch along
with (optionally) the commit ID or commit title of all commits that
are part of the topic. This is useful for scripts that needs a list of
the available topics (e.g. in a prepare-commit-msg git hook).

Signed-off-by: Brian Kubisiak brian@kubisiak.com

[brian-kubisiak-skydio]

Reviews in this chain:
└#141 toolkit: Add list-topics command

[brian-kubisiak-skydio]

#	head	base	diff	date	summary
0	e469eb4c	a05fd5eb	diff	Jan 10 9:22 AM	2 files changed, 16 insertions(+)
1	05bbdccb	a05fd5eb	diff	Jan 11 6:14 AM	2 files changed, 18 insertions(+), 2 deletions(-)

[jerry-skydio]

is the commit id specifically useful here? i'd think users would prefer having commit title instead

i'd recommend the following:

list-topics just prints topics newline separated
with --commit-id, lists commit ids newline separated as well. so there'd be 2 newlines between different topics
with --title, lists commit titles newline separated similar to above

that should in theory work with what you want and is more flexible. newline is so we don't run over the edge of the screen with topics that have a lot of commits

[brian-kubisiak-skydio]

is the commit id specifically useful here? i'd think users would prefer having commit title instead

Yes the commit id is much more useful for scripts that parse the output.

list-topics just prints topics newline separated
with --commit-id, lists commit ids newline separated as well. so there'd be 2 newlines between different topics
with --title, lists commit titles newline separated similar to above

Done. Might be worth considering doing something like " " followed by the list of commits instead of seperating topics by the double-newline, which I think is marginally simpler to parse from a script (and matches what git does in several places).