These are mostly minor mistakes I've encountered while working on the
removal of StringView(char const*). The usage of builder.put_string over
Format<FormatString>::format is preferrable as it will avoid the
indirection altogether when there's no formatting to be done. Similarly,
there is no need to do format(builder, "{}", number) when
builder.put_u64(number) works equally well.
Additionally a few Strings where only constant strings were used are
replaced with StringViews.
This isn't a complete conversion to ErrorOr<void>, but a good chunk.
The end goal here is to propagate buffer allocation failures to the
caller, and allow the use of TRY() with formatting functions.
This patch adds persistent indices to models. A PersistentModelIndex is
a ModelIndex that will survive most model updates (provided that the
data the PersistentModelIndex points to has not been removed by the
model's data store). PersistentModelIndex objects can be safely held
by objects outside the model they originated from.
