Old system was hard to track in terms of usage and it's application of
'components' properties directly to elements was shoddy.
This routes usage via the components service, with element-specific
component usage tracked via a local weakmap.
Updated existing found usages to use the new system.
- Updates old components to newer format, removes legacy component
support.
- Makes component registration easier and less duplicated.
- Adds base component class to extend for better editor support.
- Aligns global window exposure usage and aligns with other service
names.
Quick patch to clear the gallery display when getting the first page.
Duplication of the galler was occuring due to the mulitple upload events
loading the gallery mulitple times while only clearing the existing
gallery at the start of all refreshes.
A bit flashy in terms of user experience, as there will still be
mulitple load/clear events but fixes the duplication. Could be done more
elegently in future by communicating up image upload counts.
For #3160