augmentDatabase doesn't pick up new indexes added via project code extensions

[michalkleiner]

When custom code adds an index to e.g. SiteTree table, after the project was established for some time, augmentDatabase doesn't update the _Live and _Versions (and potentially other custom stages) tables with that index.

[emteknetnz]

That seems like a rather large oversight, particularly for the Live table which would benefit the most from it since that's what used the vast bulk of the time

Presumably, based on the title of this issue, this is only applicable for extensions applied to DataObject, and not new models that extends DataObject

Where it should be adding the indexes
https://github.com/silverstripe/silverstripe-versioned/blob/1/src/Versioned.php#L943

Extension point
https://github.com/silverstripe/silverstripe-framework/blob/4/src/ORM/DataObject.php#L3650