LI-FLIM: add modulo support for phase and frequency data

Phases are added to ModuloT; frequencies are added to ModuloZ.  This is
consistent with how phases/frequencies are handled in other formats.

Fixes #12290.
Tidy up a few lingering series population issuse

The series count is now at most 2, so extra bookkeeping to divide
primary images from background images is not necessary.
Merge pull request #1197 from melissalinkert/rebased/dev_5_0/liflim-modulo

Add modulo support for LI-FLIM data (rebased onto dev_5_0)