Automatic generation of client secrets for test environment

[mtwardawski]

During provision of Keycloak in the test environement client secret were set. At the moment these secrets are hard-coded in provision.sh.

These secrets were also reused in the docker compose file in .ci/docker/edgar/.

Probably there is a way to generate these secrets which are UUID's automatically and random at start up.

Linux provides a tool uuidgen which generates these UUID's. The tool may probably be used to generate secrets beforehand and be reused in other files, without hardcoding them somewhere.

Perhaps this can be reused for other UUID's in the test environment too.

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As a second step, the keys stored in resources/development/tls/ should be automatically generated as well.