Formerly an SOTemplate was default constructed and its elements
added using push_back(). This left open the possibility of a
malformed SOTemplate if adding one of the elements caused a throw.
With this commit the SOTemplate requires an initializer_list of
its elements at construction. Elements may not be added after
construction. With this approach either the SOTemplate is fully
constructed with all of its elements or the constructor throws,
which prevents an invalid SOTemplate from even existing.
This change requires all SOTemplate construction to be adjusted
at the call site. Those changes are also in this commit.
The SOE_Flags enum is also renamed to SOEStyle, which harmonizes
the name with other uses in the code base. SOEStyle elements
are renamed (slightly) to have an "soe" prefix rather than "SOE_".
This heads toward reserving identifiers with all upper case for
macros. The new style also aligns with other prominent enums in
the code base like the collection of TER identifiers.
SOElement is adjusted so it can be stored directly in an STL
container, rather than requiring storage in a unique_ptr.
Correspondingly, unique_ptr usage is removed from both
SOTemplate and KnownFormats.
Some classes had virtual methods, but were missing a virtual
destructor.
Technically, every unit test that inherits from the Beast test suite
would get flagged by `-Wnon-virtual-dtor` but I did not think it would
be a great idea to go sprinkle a virtual destructor for every Ripple
test suite.
Add support for the SignerListSet transaction as a step toward
multi-sign support.
As part of the SignerListSet implementation, add InnerObjectFormat
templates (similar to TxFormats and LedgerFormats) and enforce them
in STObject, STArray, and STParsedJSON.
