[Statistics] Dashboard Override

[skarya22]

Brief summary of changes

• Brought over changes from CCNA override
  • Ability to download chart data as csv, and download chart as png
  • Click chart for pop-up
  • Change between pie and bar chart for applicable charts
• Also added overrides for a filtering option on project, site, visit and status
• Introduced ability to filter by cohort'
• Refactored code to be more reusable
• Two charts were added from CCNA (Ethnicity and Age). Note that the "unknown" values are those with null ethnicity, and the ones with "Other" have ethnicity "other"

Link(s) to related issue(s)

• Resolves Dashboard Graph redo #7984 (Reference the issue this fixes, if any.)

##Notes:
in raisinbread there are 107 participants who have a DoB > date_registered

So for the age chart, I set it to only include those with DoB <= date_registered to prevent this happening with raisinbread: