Cleanup: lib.php and locallib.php

[jrchamp]

In 812974f, I removed some long-forgotten todo tags, so it might be good to review the code in light of the updated developer guide.

• [ ] Check Moodle's list of functions that are expected to be in a plugin's lib.php. Are we missing any new ones? Bonus points for deciding if/why we want to implement them.
• [ ] Determine what the unimplemented functions in mod/zoom/lib.php are supposed to do. Bonus points for deciding if/why we want to implement them.
• [ ] Check the functions that are currently in mod/zoom/lib.php, but are internal/"local" to the Zoom plugin.
• [ ] Move all functions from locallib.php and the misplaceed functions in lib.php to appropriately namespaced classes.

Unimplemented functions

https://github.com/ncstate-delta/moodle-mod_zoom/blob/812974f4b6f8538eea6693e7219a272459ce0844/lib.php#L439-L493 https://github.com/ncstate-delta/moodle-mod_zoom/blob/812974f4b6f8538eea6693e7219a272459ce0844/lib.php#L892-L979

Misplaced functions

These functions should probably have been in locallib.php to begin with, but Moodle's current recommendation is to move supporting functions that do not need to be in lib.php to an autoloaded class in the plugin's classes directory.

https://github.com/ncstate-delta/moodle-mod_zoom/blob/812974f4b6f8538eea6693e7219a272459ce0844/lib.php#L215-L351 https://github.com/ncstate-delta/moodle-mod_zoom/blob/812974f4b6f8538eea6693e7219a272459ce0844/lib.php#L553-L624 https://github.com/ncstate-delta/moodle-mod_zoom/blob/812974f4b6f8538eea6693e7219a272459ce0844/lib.php#L992-L1272

[jrchamp]

Please note that mod_zoom_update_tracking_fields() is set as a callback in the module settings, so this may need to stay in lib.php if set_updatedcallback() does not allow for namespaced class methods.