Accept a boolean value for the complete field of storage_manager config

[evshary]

Fix #1942

I keep the string type for backward compatibility.

[github-actions]

PR missing one of the required labels: {'new feature', 'documentation', 'breaking-change', 'enhancement', 'internal', 'dependencies', 'bug'}

[codecov]

Codecov Report

Attention: Patch coverage is 14.28571% with 6 lines in your changes missing coverage. Please review.

Project coverage is 70.78%. Comparing base (e8663bd) to head (980acbc).
Report is 17 commits behind head on main.

Files with missing lines	Patch %	Lines
plugins/zenoh-backend-traits/src/config.rs	14.28%	6 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #1991      +/-   ##
==========================================
- Coverage   70.88%   70.78%   -0.11%     
==========================================
  Files         365      365              
  Lines       61666    61670       +4     
==========================================
- Hits        43713    43654      -59     
- Misses      17953    18016      +63     

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