Add support for multiple sources in lightcurve generation and plotting

[AmberLee2427]

multiple source flux columns in lightcurve

• Implemented a strict flux conservation sanity check in the python plotting module to ensure the sum of source fluxes aligns with the true flux.
• Enhanced the python plotting functions to optionally display fluxes for two sources.
• Updated the lightcurve output to include relative fluxes for both sources in the output files.
• Modified the lightcurve generator to compute and store individual source magnifications for binary source events.
• Adjusted the smoke test runner to correctly reference parameter files for binary source cases. (smoke bug)
• Expanded the event structure to accommodate magnifications for both sources.
• Ensured memory allocation for new source magnification vectors during setup.
• Fixed malformed fits files from outputLightcurve.cpp (src bug)

[AmberLee2427]

If John wanted the magnifications, not individual flux components, I can add that too.

[AmberLee2427]

Specific addition to the lightcurve generator were:

	    if(Paramfile->multiple_sources && Event->scompanions.size()>0)
	    {    
...
			// Store individual source magnifications
			Event->Asrc1[idx] = amp;
			Event->Asrc2[idx] = amp2;
...
	    } else {
		
			Event->Asrc1[idx] = amp;
			Event->Asrc2[idx] = 0.0; // No second source
...

[mtpenny]

Thanks Amber - this will be helpful! I'm approving the requests for now, but I have a couple of requests - at least one is annoying, sorry.

1. Can you change to using mu instead of A to differentiate it from the relative flux which is using A currently (terrible choice I know)
2. (the annoying one) can we 2-d vectorize these, please to enable future development of more complicated source systems. For computational efficiency I think the first index should be source number, and the second should be observation epoch (i.e., each magnification curve is a vector inside a vector of vectors.