[Util] Proper network error handling in VK auther.

Probably fixes #1332.
[Azoth Murm] Zero-initialize self entry.
[Azoth Murm] Implement IExtSelfInfoAccount.
[Interfaces] Avoid string duplication.
[Interfaces] Added Media event cat/type for #1333.
[Interfaces] Support AllowedFields in ANFieldData for #1333.
[Util] Introduced GetStdANFields() for #1333.
[AN] NotificationRulesWidget::GetCurrentCat() for #1333.
[Util] Build fix.
[AN] Code style fixes.
[AN] Support standard fields in MatchConfigDialog for #1333.
[AN] Support Media category/types for #1333.
[Interfaces] More media fields for #1333.
[AN] Support std fields in NotificationRulesWidget for #1333.
[Util] Return all fields if type is empty for #1333.
[AN] Initialize CW_.
[AN] Pass field data to TypedMatcherBase::Create() for #1333.
[AN] Support fixed values list for #1333.
[AN] Styling fixes.
[LMP] Emit state change entity, closes #1252.