[#22] Improve 4.x support

[matthewhilton]

Related to #22

Note in 4.4+ Whoops will capture exceptions when using this plugin - its been logged here https://tracker.moodle.org/browse/MDL-80759

To do:

• Check compatibility with older versions - does this need a stable branch fork
• Update README
• Switch CI to reusable workflows so 4.0+ is tested https://github.com/catalyst/catalyst-moodle-workflows

[p8nut]

i was able to make the plugin works with the 4.3 by following your changes and commenting the line $event->set_legacy_logdata(array(SITEID, 'webservice', $this->functionname, '' , getremoteaddr() , 0, $this->userid));
(line 316)

[golenkovm]

Thanks @matthewhilton I've cherry picked your commit along with some additional changes. As this turned out to be only 4.2+ compatible I cut a new stable branch https://github.com/catalyst/moodle-webservice_restful/tree/MOODLE_402_STABLE . Closing this PR.

Cheers,
Misha