fix: Do not print sensitive information to output on POLARS_VERBOSE

[nameexhaustion]

We often request logs with POLARS_VERBOSE turned on - to prevent accidental key exposure we should not log any sensitive information. This PR instead introduces POLARS_VERBOSE_SENSITIVE for allowing logging of sensitive information.

[codecov]

Codecov Report

Attention: Patch coverage is 88.23529% with 2 lines in your changes missing coverage. Please review.

Project coverage is 79.78%. Comparing base (3696e53) to head (d6ff26e).
Report is 4 commits behind head on main.

Files with missing lines	Patch %	Lines
crates/polars-core/src/config.rs	83.33%	2 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main   #20797      +/-   ##
==========================================
- Coverage   79.78%   79.78%   -0.01%     
==========================================
  Files        1561     1561              
  Lines      222015   222027      +12     
  Branches     2533     2533              
==========================================
+ Hits       177135   177139       +4     
- Misses      44296    44304       +8     
  Partials      584      584              

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.