Closes#4719
More groups can be added to the enum, and re-defined via their type-char column.
Updating translations will automatically add those types to the list of translatables.
Fixes the Dark Mode bug where the first tab of the Event flag/work editor (LGPE) didn't respect dark mode; now that all all event editors are sub-tabbed, we use the workaround present in all (on shown flip back to the first tab).
* Move pkhex.drawing calls out of form constructors
designer doesn't like it; if Main can't be designed then there's some
call that it can't process for whatever reason
* Add netcore3 targeting
Closes#2198 by adding a netcore3 build option
Closes#2391 by retaining designer functionality and net46 builds