improve functional tests

improve functional tests

- make scripts with "sed" compatible with BSD and macOS

- remove illegal reflective access warnings introduced by JDK11
  - create a file tests/reflectwarn.sh with the right JDK_JAVA_OPTIONS
    variable content.
    sourcing this file at build or runtime removes the warnings.
    But instead, it generates a long note in stderr that still pollutes
    nosetests results.
- in functional tests, move sims and controller stderr to a file to
  prevent that note from polluting nosetests results.

https://dev.to/erichelgeson/removing-illegal-reflective-access-warnings-in-grails-4-393o

JIRA: TRNSPRTPCE-192 TRNSPRTPCE-197
Signed-off-by: guillaume.lambert <guillaume.lambert@orange.com>
Change-Id: I04156ab104d7420d1eb2d180579593c67293175b