Map: Update floating plot plugins for varying sample size records

[d-callan]

We need to be able to accommodate in plot.data cases where one row in a data table does not represent a single 'record'. ex: the popbio megastudy sample entity contains both individuals and pooled samples. in order to average across these two types of records, we need to know how many individuals are in the pooled sample and do a weighted average. We also need to be able to accommodate cases where we need to impute 0s for tall data. This ticket is to update the APIs and plugins for the floating charts so that this data can be passed to R appropriately.

Each plugin will now have to:

1. include config to indicate, when the output entity requires it, a variable which can be used to find the sample size per record
2. include config to indicate, when a variable requires it, that it has a row-dependent vocabulary, which ancestor variable defines the complete vocabulary and what filters were applied to that variable
3. hit a dedicated metadata endpoint to find row-specific vocabularies
4. pass the vocabulary, the variable filters, and the sample sizes per record to plot.data

Depends on #264
Depends on VEuPathDB/plot.data#220
Depends on VEuPathDB/EdaLoadingIssues#62

Related to #266