SQL Server: how to config HasFillFactor on a string primary key

[kzhui125]

I don't find HasFillFactor after HasName

[roji]

We have HasFillFactor on IndexBuilder, but we're missing it on KeyBuilder. There may be other similar missing index options.

[ajcvickers]

Note from triage: maybe we should have an API consistency check here to catch things added for indexes that could also apply to the primary key constraint.