Improved _getEnviron to deal with multiple variables in the evaluated string

[bcouturi]

Improved _getEnviron to deal with the case when multiple variables are to be evaluated in the string.
Previously it was only looking for the first ${ and the last }. I did a qucik fix that looks for all ${ } in the string. Using a parser or a library to do this would be better, but it seems that DDCore can be built without boost ?

BEGINRELEASENOTES

• Improved _getEnviron to deal with the case when multiple variables are to be evaluated in the string
  ENDRELEASENOTES

[bcouturi]

Included suggestions from A.Sailer

[github-actions]

Test Results

       6 files         6 suites   8h 0m 21s ⏱️
   358 tests    357 ✔️ 0 💤 1 ❌
1 058 runs  1 056 ✔️ 0 💤 2 ❌

For more details on these failures, see this check.

Results for commit f82a9b4.

[andresailer]

Expected failures, and the "rich" again:
TEST: failed with average number of hits = 248.72 (expected 230+/-15)