Remove some SVG types from bindings map

Our maps are string-based and assume there's only one one @Native
class with a given name. This isn't true for these four classes,
where there are two types with the same name for each one.
This then results in us dropping the definition of one of the
two types.

Since one of the two types is essentially unused, we should choose
to drop that one instead for now. Long-term, we should deprecate
the unused types or change our conformance handling to handle
multiple types with the same name. We could also choose to unify
both definitions, but this may lead to either false positives or
renames of members being dropped.

This allows us to catch uses of the types that are actually used.

Change-Id: I9386cad5b014bee60cd72d21cdf0546640138704
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/341331
Reviewed-by: Sigmund Cherem <sigmund@google.com>
Commit-Queue: Srujan Gaddam <srujzs@google.com>