Demote (to level 1 from DEBUG) and speed-up API doc logging (parseParameters)

[mih]

Previously, log messages like this would appear at DEBUG level:

[DEBUG] parseParameters: Given "exclude_special_remotes: bool, optional
  if True, don't return annex special remotes", we split into [('exclude_special_remotes', "exclude_special_remotes: bool, optional\n  if True, don't return annex special remotes")]

These are very verbose and large in number, making debug
output needlessly complicated to read.

Moreover, they log the outcome of a trivial operation that practically
never fails in production code, at a comparatively high level (DEBUG),
and they did it in an expensive way that actually built the log string
unconditionally of the effective log level.

This change demote the log level to the lowest possible, and uses a proper
logging pattern that avoid needless string operations.

Changelog

Not needed

[codecov]

Codecov Report

Merging #6635 (ae7cce2) into maint (eb55f5a) will not change coverage.
The diff coverage is 100.00%.

@@           Coverage Diff           @@
##            maint    #6635   +/-   ##
=======================================
  Coverage   91.17%   91.17%           
=======================================
  Files         353      353           
  Lines       44496    44496           
=======================================
  Hits        40568    40568           
  Misses       3928     3928           

Impacted Files	Coverage Δ
datalad/dochelpers.py	84.74% <100.00%> (ø)

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[yarikoptic]

I remember there was some interaction between 1 and "something else" . That is why we hardly ever have logging at that low level

$> git grep -A1 '\.log($'
datalad/cmd.py:                lgr.log(
datalad/cmd.py-                    5,
--
datalad/core/local/repo.py:            lgr.log(
datalad/core/local/repo.py-                5,
--
datalad/runner/coreprotocols.py:            lgr.log(
datalad/runner/coreprotocols.py-                5,
--
datalad/runner/protocol.py:        lgr.log(
datalad/runner/protocol.py-            8,
--
datalad/runner/runnerthreads.py:        lgr.log(
datalad/runner/runnerthreads.py-            5,
--
datalad/support/sshconnector.py:            lgr.log(
datalad/support/sshconnector.py-                5,

$> git grep '\.log(1'    
datalad/dataset/gitrepo.py:        lgr.log(1, "Finalizer called on: GitRepo(%s)", path)
datalad/support/annexrepo.py:        lgr.log(1, "Finalizer called on: AnnexRepo(%s)", path)

but IIRC it was relating to custom special remotes and custom implementation of those is gone, so might no longer be pertinent. I personally would have not made it 1 but something like 5 (HEAVYDEBUG) but I also do not care enough. Let's proceed. I will release maint with this