Support large list/map constructors

[manuranga]

It has been previously reported and fixes that the list constructor at https://github.com/ballerina-platform/nballerina/blob/fca28a11dadf2a78b6cb010690505a184fd16020/compiler/modules/front.syntax/tests/testParser.bal#L189 is giving method too large error.

It is reappearing as we keep adding more items to the list. We are planning to move away from having it in source to a separate JSON file. With this, jBallerina will lose a valuable real world test case of having large constructors in files.

Since working with JSONs is a primary use case for ballerina, I think it will be common for users to paste huge JSON files into source code. I propose we plan for the by having an integration test with large constructors for both map and lists. We should also guarantee the compilation time is not affected by large constructors.