Strat Interval Sample SESAR

[ClairePMartin]

Describe the bug
Add SESAR function to strat interval polygon spot

To Reproduce
Are you able to reproduce the problem in a new project after restarting the app?
Yes

[jessicagood]

The IGSN upload is not allowed for samples in any polygon spot, not just intervals. Perhaps for non-point spots we can grab a centroid and then still allow the IGSN connection.

[ClairePMartin]

@jessicagood is it easier to allow sesar for any polygon and calc the lat/lon or just add sesar for interval polygons only which inherit the strat section lat/lon?