DM-39902: add support for deprecating connections and connection templates

[TallJimbo]

Checklist

• ran Jenkins
• added a release note for user-visible changes to doc/changes

[TallJimbo]

This PR is just a re-branching of #349, which has already been reviewed; I'm just splitting the pipe_base off from the other packages to land it sooner and improve ticket granularity.

[codecov]

Codecov Report

Patch coverage: 94.44% and project coverage change: +0.02 🎉

Comparison is base (e6f13a4) 82.72% compared to head (24550ee) 82.74%.

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #351      +/-   ##
==========================================
+ Coverage   82.72%   82.74%   +0.02%     
==========================================
  Files          66       66              
  Lines        7246     7281      +35     
  Branches     1408     1301     -107     
==========================================
+ Hits         5994     6025      +31     
- Misses       1005     1007       +2     
- Partials      247      249       +2     

Impacted Files	Coverage Δ
python/lsst/pipe/base/config.py	70.12% <ø> (ø)
python/lsst/pipe/base/graph/_implDetails.py	44.69% <ø> (ø)
python/lsst/pipe/base/graphBuilder.py	63.68% <ø> (ø)
python/lsst/pipe/base/connections.py	78.14% <85.71%> (+0.29%)	⬆️
python/lsst/pipe/base/connectionTypes.py	87.30% <100.00%> (+0.20%)	⬆️
tests/test_connections.py	99.04% <100.00%> (+0.23%)	⬆️

... and 1 file with indirect coverage changes

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