ROM workflow for restart file collection and POD basis training

[dreamer2368]

This PR must be rebased after PR #229 is merged to ROMFPMD.

src/rom_main.cc is re-written, copying from the main driver src/main.cc. This will be compiled into an executable mgmol-rom. This ROM driver will handle the entire workflow of ROM. Currently, only the restart file collection + POD training is implemented.

• The ROM workflow routines will be implemented in src/rom_workflows.h and src/rom_workflows.cc.
  • The restart file collection + POD training is implemented as readRestartFiles.
  • This does not require saving libROM snapshot file at offline FOM simulation. The standard mgmol restart files can be used for POD basis generation.

Usage:

• The restart file directories should be renamed following a certain string format that takes an integer. This string format should be specified in ROM.offline.restart_filefmt.
• mgmol-rom will read the restart files starting from an index specified in the input ROM.offline.restart_min_idx, to another index specified in the input ROM.offline.restart_max_idx.

For example, examples/Carbyne/carbyne.rom.cfg specifies:

[ROM.offline]
restart_filefmt=snapshot0_%03d
restart_min_idx=0
restart_max_idx=1
basis_file=carom

Reading this input file, mgmol-rom will search for directories snapshot0_000 and snapshot0_001. The resulting POD basis will be stored in a directory carom.

Minor change

Docker container now has hdf5-tools installed.