Update `CharSequenceToObjectConverter` so that conversion that would
apply using an `ObjectTo...` converter now favors `toString()` based
conversion.

Prior to this commit, when converting a `CharSequence` to a `Collection`
the `ObjectToCollectionConveter` would be picked instead of the
`StringToCollectionConverter`. This resulted in a `Collection`
containing a single `String` value, rather than the expected list
of values split around ",".

Fixes gh-25057