-Adds field for type nullability for IDL operations
-Adds field for conversions to reflect input and output type nullability
--based on implementation
-Corrects generic object types to include nullability
-Changes 'any' types to dynamics
-Adds nullability to types in various operations
-Converts finals and non-initialized non-nullable fields to getters and
setters
--TODO: convert these to native instead of JS inline
-Modifies nullability for annotations and removes annotations from
setters
Change-Id: Iab19830fd1d7f37b170a4da8672f922c3f9b0863
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/132967
Commit-Queue: Srujan Gaddam <srujzs@google.com>
Reviewed-by: Sigmund Cherem <sigmund@google.com>