feat: Replace pendulum by home-made duration-to-words function

[dbaty]

pgcli uses Pendulum to display the query execution time in words:

> select pg_sleep(62)
+----------+
| pg_sleep |
|----------|
|          |
+----------+
SELECT 1
Time: 62.066s (1 minute 2 seconds), executed in: 62.063s (1 minute 2 seconds)

Pendulum 3 (which has been released in December 2023 and is now
written in Rust) does not build on 32-bit architectures [1]. As such,
installing pgcli on such architectures fails. We could pin Pendulum
to version 2 (which was written in Python and builds "everywhere"),
but requiring a whole library and its own dependencies for such a
small feature seems unwarranted.

This commit thus removes the requirement on Pendulum and replaces it
by a simple "duration-to-words" function.

Fixes #1451.

[1] Upstream issue: sdispater/pendulum#784

Checklist

• I've added this contribution to the changelog.rst
• I've added my name to the AUTHORS file (it's already there).
• I installed pre-commit hooks (pip install pre-commit && pre-commit install), and ran black on my code.
• Please squash merge this pull request (uncheck if you'd like us to merge as multiple commits)

[dbaty]

I tried to be consistent with what Pendulum, except:

1. The function uses units up to hours, while Pendulum uses days and weeks, too. For example, we'll show "25 hours 10 second", while Pendulum would have shown "1 day 1 hour 10 seconds". I don't think we care and the code is (slightly) simpler this way.

2. The function handles sub-second durations slightly differently (see unit tests), but pgcli does not use the function for such small durations anyway. So there is no change in behaviour, here.

3. The function is not written in Rust. We probably could save a few microseconds by writing a Rust extension. And we would look way more cool... Yeah, well, too bad. 😉

[codecov-commenter]

Codecov Report

All modified and coverable lines are covered by tests ✅

Comparison is base (96eb37f) 79.88% compared to head (da189aa) 80.04%.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #1452      +/-   ##
==========================================
+ Coverage   79.88%   80.04%   +0.16%     
==========================================
  Files          25       25              
  Lines        3047     3067      +20     
==========================================
+ Hits         2434     2455      +21     
+ Misses        613      612       -1     

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[j-bennet]

The function is not written in Rust. We probably could save a few microseconds by writing a Rust extension. And we would look way more cool... Yeah, well, too bad.

😂

Maybe one day, we'll rewrite pgcli in Rust to be cool. But not today.

[j-bennet]

LGTM. Feel free to merge, once the changelog is updated.