* go-secure-stdlib/parseutil to v0.1.4
* add TypeCommaStringSlice for json.Number
* add changelog entry
* upgrade go-secure-stdlib/parseutil to v0.1.4 in sdk
* move json number TypeCommaStringSlice test
* go mod download for api; go mod tidy
* Refactor table driven tests to use subtests
* sdk/framework: add TypeSignedDurationSecond FieldType
Adds the TypeSignedDurationSecond FieldType which accepts positive and
negative durations. The existing TypeDurationSecond FieldType does not
accept negative durations.
* Add tests for 0 for TypeDurationSecond and TypeSignedDurationSecond