check consistency in gtbin of input events list with parameters

[jasercion]

migrated from STGEN-166

gtbin should check that the selections applied to the input events list prior to calling gtbin cover the space required for the projection.
This means:

• check that the spatial selection covers the square defined by the nxpix, nypix, binsz, coordsys, xref, yref, axisrot, proj parameters (this is non trivial for general projections)

• check that the energy selection covers the interval defined by the ebinalg, emin, emax, enumbins parameters (this is trivial)

When those conditions are not met, the output will be unsuitable for scientific analysis and the user should at least get a warning.
My preferred solution would be to throw an error by default and add a parameter (such as checkselection) which could be set to no voluntarily by the user who wants to override the default.