bookmarks: add support for log-like template keywords and functions This is basically the same as 5d9b765dbe15 "tags: unblock log-like template keywords and functions."

fix: add progress bar for number of file revisions processed This ensures responsiveness when the configured tools are slow or numerous. Differential Revision: https://phab.mercurial-scm.org/D3848

fix: use a worker pool to parallelize running tools This is important for usability when tools are slow or numerous. Differential Revision: https://phab.mercurial-scm.org/D3846

worker: support more return types in posix worker This allows us to return things that aren't tuple(int, str) from worker functions. I wanted to use marshal instead of pickle, but it seems to read from the pipe in non-blocking mode, which means it stops before it sees the results. The windows worker already supports arbitrary return values without serialization, because it uses threads instead of subprocesses. Differential Revision: https://phab.mercurial-scm.org/D3845

debug: process --debug flag earlier This allow the verbosity level to be set correctly during extension initialization.

test: stop passing --quiet in a run dedicated to debug output The goal of the run is to display some debug output. Passing --quiet in this case is strange.