Fix: Handle new lines inside block string correctly

[langpavel]

This fixes #1636

[langpavel]

Hi @IvanGoncharov
Can I kindly ask you for review?
Thanks!

[IvanGoncharov]

@langpavel Thanks for PR 👍
Please expand tests and I will merge this PR.

P.S. It's a good temporary solution but I don't like duplication of new line code handling and having special handling of block strings.
I think in long run we need to implement a common function for advancing lexer to the next character. Maybe even unify with CharacterStream from language server:
https://github.com/graphql/graphql-language-service/blob/master/packages/parser/src/CharacterStream.js

[langpavel]

Ok, I will try refactor to new lexer method advanceLine, existing tests should cover this so no need to expand tests for block string
CharacterStream will be nice, but it will be huge change, (may be breaking..?)

[langpavel]

@IvanGoncharov I extracted consumeNewline function so newlines are handled on one place.

[IvanGoncharov]

existing tests should cover this so no need to expand tests for block string

@langpavel Existing tests don't check that \r\n or \n\r advance line counter by one.

[langpavel]

Ok, I will add more tests

[langpavel]

@IvanGoncharov I added your test case and also added column assertion

[IvanGoncharov]

@langpavel Thanks 👍
Merged 🎉

[langpavel]

Thanks! Happy new year 🎉