[common_test] Extend valid interval for approximate timer values in tests

When matching the result of tests of timetrap timeouts, the actual
time is measured against the expected time, and an interval of +/- 2%
was seen as correct result. This turned out to fail on some platforms
and is now changed to 5%.
[common_test] Extend timeout values for slave nodes in ct_master_SUITE

Some tests in ct_master_SUITE failed on some platforms with
boot_timeout when trying to start slave nodes. The default timeout
value was 3 seconds, and it is now extended to 10 seconds in these
tests.

To avoid similar errors with init_timeout and startup_timeout, these
are both exteded from 1 second default value to 10 seconds in this
test.
[common_test] Changed call to publick_key to use documented interface

Earlier used 'OTP-PUB-KEY':encode/2 - now public_key:der_encode/2 instead.
[common_test] Avoid hanging ct@host node if crypto does not exist

ct_netconfc:init_per_suite called ct_test_support:init_per_suite
before checking if crypto exists. This caused the slave node (ct@host)
to be started even though the suite would be skipped when crypto did
not exist - which in turn caused a hanging ct node since end_per_suite
is not run in a skipped suite. This has been corrected.
[common_test] Extend timetrap time in ct_hooks_SUITE

This suite often fails with timetrap timeout on some test machines.
Merge branch 'siri/common_test/minor_test_fixes/OTP-10483'

* siri/common_test/minor_test_fixes/OTP-10483:
  [common_test] Extend timetrap time in ct_hooks_SUITE
  [common_test] Avoid hanging ct@host node if crypto does not exist
  [common_test] Changed call to publick_key to use documented interface
  [common_test] Extend timeout values for slave nodes in ct_master_SUITE
  [common_test] Extend valid interval for approximate timer values in tests