Previously we only compiled the typings files, in ngcc, if there was
an ES2015 formatted bundle avaiable. This turns out to be an artificial
constraint and we can also support typings compilation via ES5 formats
too.
This commit changes the ngcc compiler to attempt typings compilation
via ES5 if necessary. The order of the formats to consider is now:
FESM2015, FESM5, ESM2015, ESM5.
FW-1122
PR Close#29092