path enhancements rollup issue

[cyrush]

This issue links to several file path and naming issues.

They may need simple one off fixes and reviewing could inform need for a holistic approach to dealing with paths:

#1400
#1289
#1285
#1368

[cyrush]

@emily-howell this is the meta issue I promised to create for the various path related improvements we want to tackle.

[emily-howell]

Thanks, I will take a look at these

[cyrush]

For all extracts --- we should support fmt style strings that can pull from metadata:

"_{cycle:05d}"
"_{time:0.4f}"
"_{family:05d}" 

cycle and time are straight forward
family looks for an existing file and finds the next in a series.

For the blueprint relay extract case -- these can be applied before we pass the base name.

[cyrush]

A subset of what we want exists here:

ascent/src/libs/ascent/utils/ascent_string_utils.hpp

Line 28 in bcd4536

std::string expand_family_name(const std::string name, int counter = 0);

But, we want to evolve to unified function that will support all of these cases, and also only check for files when necessary on rank 0.

std::string expand_path(const std::string &path,int mpi_comm_id);

The actual string substitution can be handled by conduit's wrapped format method that binds named nodes to args:

https://github.com/LLNL/conduit/blob/67ee1503d366b88b5c97fc43d6ab8e8e72009aec/src/libs/conduit/conduit_utils.hpp#L495