Deprecate NonCopyable in favour of explicitly deleted ctors

[marcosbento]

Description

An attempt to modernize the code base, by deprecating the "old style" NonCopyable in favour of explicitly deleting copy ctor/copy assignment operator.

This follows the advice of the CppCoreGuidelines, which states = delete is preferred -- see the discussion isocpp/CppCoreGuidelines#1354 (comment).

The proposed effectively remove a "small" eckit dependency

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/odc/pull-requests/PR-48

[codecov-commenter]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 86.91%. Comparing base (aafb8f0) to head (cfba30a).

Additional details and impacted files

@@             Coverage Diff             @@
##           develop      #48      +/-   ##
===========================================
- Coverage    86.94%   86.91%   -0.03%     
===========================================
  Files          188      188              
  Lines        15116    15021      -95     
  Branches      1363     1363              
===========================================
- Hits         13142    13055      -87     
+ Misses        1974     1966       -8     

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