This tests several variations of SEB config files, to ensure Moodle
is able to parse them and generate a config key hash that matches
what SEB expects.
Additional values have been added to the unencrypted_win_233.seb
config file to cover the existence of floating point values,
ensuring they are serialized correctly. The config hash value
has been updated in real_ck_hash_provider to reflect the change.
Also added coverage information to the test case class docblock.
0be064b328