Disallow cumulative markers for overlapping datasets

[elaragon]

We should add an extra field allow_cumulative_markers for datasets.

This field should be false except for these datasets:

• 2 ASIA Events
• 3 IRIS Claims
• 12 Decidim PAM Meetings
• 14 DDDC Meetings

Then, main.js should be updated to only show the cumulative option when (1) the selected visual model is map, and (2) the selected dataset is one from the above list.