Fix broken parse-literal-occurences on syntax errored code

[Chnapy]

Literal occurences parsing was done by @graphql-tools/graphql-tag-pluck, which uses babel/parsel behind. Babel does not work with syntax broken code, so graphql-tag-pluck cannot be used for this issue.

In a previous iteration, a solution using TS api with AST visitor was made, which works with syntax broken code, even with better performances => first commit of this PR #22. This solution is clearly better.

• Remove @graphql-tools/graphql-tag-pluck.
• Instead, use of first commit of this old PR Refactor literal parser using AST instead of regex #22

fix #41