Print non-default attribute types in optional attr dictionary

In optional attribute dictionary used, among others, in the generic form of the
ops, attribute types for integers and floats are omitted.  This could lead to
inconsistencies when round-tripping the IR, in particular the attributes are
created with incorrect types after parsing (integers default to i64, floats
default to f64).  Provide API to emit a trailing type after the attribute for
integers and floats.  Use it while printing the optional attribute dictionary.

Omitting types for i64 and f64 is a pragmatic decision that minimizes changes
in tests.  We may want to reconsider in the future and always print types of
attributes in the generic form.

PiperOrigin-RevId: 232480116