always avoid using temporary file names, and then set this option as
enabled by default.
Also change the setting key so that existing users will also get the new
default value.
Fixes#32591
These methods return a file extension to use when creating vector/raster outputs (e.g. "tif"). Generally,
it is preferable to use the extension associated with a particular parameter, which can be retrieved through
QgsProcessingDestinationParameter::defaultFileExtension(). However, in some cases, a specific parameter
may not be available to call this method on (e.g. for an algorithm which has only an output folder parameter
and which creates multiple output layers in that folder). In this case, the format returned by this
function should be used when creating these outputs.
It is the algorithm's responsibility to check whether the returned format is acceptable for the algorithm,
and to provide an appropriate fallback when the returned format is not usable.
For the c++ api dox this expands to "\c nullptr" (the
\c directive indicates a code literal value), and for sipify/Python
it expands to ``None`` (`` is sphinx annotation for literal values)
Makes for nicer dox for both c++ and Python!
