implement string numeric interpolation feature

[mbtolou]

hi.
implement string numeric interpolation feature.

https://docs.microsoft.com/en-us/dotnet/standard/base-types/standard-numeric-format-strings

like this :

select stringformat('i have {0:C} dollars .',100)
result:
i have 100.0$ dollars .

select stringformat('->{0:x20}<- .',"hello")
result:
->xxxxxxxxxxxxxxxHello<-

[filimonov]

#27680 (comment)

/cc @alexey-milovidov

Loosely related: #2770