Refactor to reduce scope of namespaces std/boost

[marcosbento]

Description

Refactor to reduce scope of namespaces std/boost

Contributor Declaration

By opening this pull request, I affirm the following:

• All authors agree to the Contributor License Agreement.
• The code follows the project's coding standards.
• I have performed self-review and added comments where needed.
• I have added or updated tests to verify that my changes are effective and functional.
• I have run all existing tests and confirmed they pass.

🌦️ >> Documentation << 🌦️
https://sites.ecmwf.int/docs/dev-section/ecflow/pull-requests/PR-262

[codecov-commenter]

Codecov Report

❌ Patch coverage is 62.60331% with 362 lines in your changes missing coverage. Please review.
✅ Project coverage is 49.25%. Comparing base (9b860c1) to head (0d58da2).

Files with missing lines	Patch %	Lines
libs/client/test/TestSinglePerf.cpp	0.00%	44 Missing ⚠️
libs/client/src/ecflow/client/ClientInvoker.cpp	43.39%	30 Missing ⚠️
libs/attribute/src/ecflow/attribute/Zombie.cpp	0.00%	17 Missing ⚠️
libs/base/src/ecflow/base/Stats.cpp	79.76%	17 Missing ⚠️
libs/node/test/TestEcfFile.cpp	85.57%	15 Missing ⚠️
libs/test/overall/harness/TestFixture.cpp	0.00%	15 Missing ⚠️
libs/test/overall/harness/ZombieUtill.cpp	0.00%	11 Missing ⚠️
libs/base/test/TestJobGenPerf.cpp	0.00%	10 Missing ⚠️
libs/node/test/parser/ParseTimer.cpp	62.50%	9 Missing ⚠️
libs/client/src/ecflow/client/Help.cpp	0.00%	7 Missing ⚠️
... and 79 more

Additional details and impacted files

@@             Coverage Diff             @@
##           develop     #262      +/-   ##
===========================================
- Coverage    49.26%   49.25%   -0.01%     
===========================================
  Files         1231     1231              
  Lines        96964    96994      +30     
  Branches     14857    14859       +2     
===========================================
+ Hits         47768    47779      +11     
- Misses       49196    49215      +19     

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