Feat: List Filters on PDF Export

[danglorioso]

• On the PDF exports for charts and heatmap, filter can be applied. Right now, it just states how many filters were applied in the title, but doesn't list exactly what those filters are what settings are selected within those filters. For example, filtering by school: it would be much more helpful to know which schools were selected in the filter when a chart was created.

Fix:

• In PDF exports, list the actual parameters that were selected within a chart export, possibly by adding a list underneath the exported graph.