Add (lots of) small caps ("SC") font families

[davelab6]

Many families have been added in recent years with small caps glyph sets, but unlike in the early years, I didn't ask for their build scripts to output "SC" families - where the lowercase glyphs are replaced with the small caps glyphs and the family name is changed to append "SC".

This was on the basis that OpenType Features would be coming soon to the API; but since that seems to be still some way away, I now would like to ask for

• a review of the library to ID which families have small caps glyph sets, and then
• a set of FB checks specific to small caps glyph sets to make sure that their coverage and associated OT features are uniformly high quality, and then
• updates to the gf builder, and upgrading of projects predating it from their per-project build scripts to it, to output the SC families in a scalable way, and then
• onboarding all the "missing" SC families for all the families that have provided them but users can't access yet need to use them

I'm proposing this as a Q2 project but it might need to slip to Q3, which would be fine.

[simoncozens]

The following fonts appear to have:

• a smcp feature
• no matching SC family
• no primary script or primary_script == Latn

• alumnisans (Builds OK)
• alumnisanscollegiateone (Builds OK)
• andadapro (Does not build due to glyphsLib bug Axis mappings completely upside down googlefonts/glyphsLib#993)
• andika (Unlikely due to unusual SIL build process)
• anton (Builds OK)
• arsenal (Builds OK if you add a config file)
• barlow (Unlikely due to issues mentioned in Update Barlow to variable font? #3625)
• barlowcondensed (idem)
• barlowsemicondensed (idem)
• baskervville (Builds OK)
• bigshouldersdisplay
• bigshouldersinlinedisplay
• bigshouldersinlinetext
• bigshouldersstencildisplay
• bigshouldersstenciltext
• bigshoulderstext
• bitter (Not gonna build because glyphsLib axis mappings also also Glyphs3-style variable syntax)
• bodonimoda (Builds OK)
• bonanova (Builds OK)
• brygada1918 (Fails to build, incompatibility in f.sups)
• castoro
• charissil
• chauphilomeneone
• corben
• cormorantgaramond (Glyphslib issue again)
• cormorantinfant (Glyphslib issue again)
• cormorantunicase
• doppioone
• ebgaramond (Stat table issue)
• edunswactfoundation
• eduqldbeginner
• ekmukta
• epilogue
• estonia
• exo
• fanwoodtext
• firasans
• firasanscondensed
• firasansextracondensed
• fragmentmono
• gentiumbookplus
• gentiumplus
• georama
• gfsdidot
• gfsneohellenic
• gideonroman
• habibi
• hahmlet
• heptaslab
• ibarrarealnova
• imbue
• istokweb
• italianno
• joan
• jura
• kufam
• lekton
• lindenhill
• literata
• merriweathersans
• mina
• miriamlibre
• monda
• montserrat
• montserratalternates
• mukta
• muktamahee
• muktamalar
• muktavaani
• neuton
• notosansdisplay
• notosansmono
• notoserifdisplay
• oflsortsmillgoudytt
• orbitron
• petrona
• piazzolla
• play
• playfair
• poltawskinowy
• poly
• praise
• questrial
• raleway
• ralewaydots
• rem
• roboto
• robotocondensed
• sigmar
• sofiasans
• sofiasanscondensed
• sofiasansextracondensed
• sofiasanssemicondensed
• sortsmillgoudy
• sourcesans3
• sourceserif4
• stixtwotext
• trispace
• varela
• vazirmatn
• worksans
• ysabeauinfant
• zillaslab
• zillaslabhighlight