New chart items

[iansargent]

• Added 3 new TrendChart items: UnemploymentTrendChart, EarningsTrendChart, and MedianAgeTrend Chart
• New aggregation logic if profile interest is set to VT statewide (still needs some tweaking)
• New api calls for special time series charts
• Documented new charts to the plots.md file

[FWJK1]

Can you update these (and all other SQL queries here) to match the paradigm for the zoning dataset?

That is, move the actual logic here into a subsection of the "serve" folder, with the SQL pumped in from .sql files (and ideally parameterized a bit better, with less repetition).

like a lot of these you could just make table a parameter you pass in. so that its "FROM {table}" or "FROM ?".

[FWJK1]

• Left comments in the post_acs5_db that apply to the post_qcew as well.
• overall good!
• TO fix:
• take the chance to port the logic over to the 'build -> serve -> API' model.
• parameterize repetive SQL and put in .sql files. See backend/serve/zoning.