* This is a deliberate break of compatibility since the field is now often
empty, for non-markers. This means code will get a more explicit error when
the name is being referenced, so it can be updated to fetch the name it needs
as needed.
* There's not a good accepted terminology for this kind of event, and for
historical reasons 'drawcall' has been the accepted term, even though
that can be quite confusing when a dispatch or a copy is a 'drawcall'.
* This is particularly highlighted by the event browser filters where
$draw() includes draws and dispatches, but $dispatch() only includes
dispatches, it's hard to intuitively understand why $draw() matches all
of these calls.
* As a result we've defined the term 'action' to cover these types of
events in the same way that we defined 'event' in the first place to
mean a single atomic API call.
* The filter icon was confusing since it had a 'refresh' badge instead of
'save/load/recent' type badge, and making the latter readable in a few pixels
is not feasible. Having the combo dropdown with saved filters is as intuitive
and works in-line.
* The current filter is preserved across runs even if it's not explicitly saved.
Saved filters are only updated with an explicit save - loading a filter then
making a change just cahnges the current scratch filter, it doesn't update the
saved filter until the user explicitly saves it.
* This is a little bit inconsistent because they are technically draws, but
they're only draws so they can include the trailing API events in a region.
* Think of it this way:
Imagine we instead made PopMarker just a normal API event (which is how we want to treat it) and instead inserted a second 'internal' draw at the end of each region to contain the popmarker. This internal draw would be hardcoded to never show up in filters no matter what - even with an empty include-all filter. But it contains the other API events so they can be selected individually and filtered in/out.
In this scenario it's functionally equivalent to just using the PopMarker as that 'internal' draw containing its own API event and making it fail all draw filters. The only difference is that users can manually filter in the PopMarker draw with flags if they want.
* We can't use the exact same interface because we want builtin filters to be
able to return specialised lambdas, but we at least register them by name.
This is helpful for ensuring the completion doesn't get out of sync, and we'll
use it next to provide function-specific completion