Some Defaults For Plot Requests are Non-Standard for PROCs

[dmsenter89]

The function SASProcCommons._makeProcCallMacro sets some defaults for PROC calls that are non-standard. Specifically, it sets the procopts plot=all by default for STAT and ETS PROCs (with an exception introduced in #514). This is non-standard; the correct procopts is plots=all (with plural s). See for example PROC TIMESERIES, PROC UCM, PROC REG, and PROC TTEST. Some, but not all, PROCs may translate plot=all to plots=all behind the scenes, but is safer to use the language default.

I propose changing the two defaults to plots=all. I'm happy to make a PR fixing this.

[tomweber-sas]

Sounds great! Thanks again for contributing fixes!