[dartfuzz] Handle more types in minimized literal generation.

Previously, the minimizer only handled a small, handpicked set of types
when replacing expressions with minimized literals of the expression's
type. This CL adds minimal literal generation for any type that has a
known constructor and generalizes handling of lists, sets, and maps.

TEST=dartfuzz

Change-Id: Ifeaacfd4dec1ba8f66f4fee9cf8c7fb74193b0d2
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/403861
Reviewed-by: Ryan Macnak <[email protected]>
Commit-Queue: Tess Strickland <[email protected]>

Author: sstrickl