ecCodesMIA 2.17.0 b7

[teresanoviello]

The motivation of the change and impact on code: This is the ecCodesMIA B7 version, also referred to as 'Reducing the heap allocation space: introducing static array pools'. This is a pull request for a branch derived from ecCodes official repository, tag "2.17.0": so please, when merging take into account to not do it against the current ecCodes "develop" HEAD. The complete changes applied are described in the file "src/ChangesB7.txt". This code is not operational. Impacts on the code: NOT all automated tests are passing, the complete output is in the file "ctest3.out". The list of not passing tests is also mentioned in the Confluence webpage 'https://confluence.ecmwf.int/x/5xg1Cw'. A full report of the ecCodesMIA project is accessible at https://gitlab.eumetsat.int/additional-data-services/eccodes-impact-analysis/-/blob/master/docs/officialdocs/ecCodesMIA_FinalReport_files/ecCodesMIA_FinalReport.md.

The author of changes accepts the "ECMWF Contributors License Agreement". In particular: 2.1. This code can be redistributed under Apache License 2.0; 2.2. This code doesn't violate anyone IPR' rights;

3.Exception to PR requirements as described in "https://confluence.ecmwf.int/display/SUP/ECMWF+software+on+GitHub": 3.1. Although this code passes some of the automated and regression tests, it is not intended as an operational version, as stated earlier.