[FEAT] Read in multiple split catalogue files in C++ interface

[MikeSWang]

Is the requested feature related to an issue?

No.

Summary

Currently only one data/random catalogue file can be specified in the .ini parameter file and loaded by triumvirate. This request extends that to multiple split catalogue files.

Alternatives

N/A

Implementation

Instead of implementing a glob or regex pattern for multiple filenames, external scripts are used to explicitly list all the desired catalogue files, delimited by a special character such as the colon :, which are then passed as a single parameter for the catalogue(s) in the .ini parameter file.

Additional context

This avoids reading in a single large file.