Make sure certain arguments in eSASS command expmap are set to recommended values

[jessicapilling]

In eSASS4DR1, the expmap tools has certain keywords which should be set a certain way, or the output exposure maps are not useful for further science.

The first: withweights=yes

• this will make the exposure map values equal to the effective on axis exposure time

The second: withdetmaps=yes

• this will include a detector map when calculating the exposure map, and will not include the edges of the detector in the calculation - as in this area the arf isn't characterised well