remsim: add the guard timeout to all test cases

As can be seen [1], it happens quite often that a test case gets
stuck and runs forever.  Most of the existing test suites have
the guard timeout to prevent this.  Let's make use of it here too.

[1] https://jenkins.osmocom.org/jenkins/view/TTCN3/job/ttcn3-remsim-test-latest/190/
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Change-Id: I3897efd2a97c3e0d487057aa7bdc2967f3424dd8
3 files changed