Revert "Merge branch 'feat-update-mermaid' into 'master'"

What does this MR do and why?

Reverts !106536 (merged) since it breaks several scripts and workflows, for instance for analyzing a webpack bundle:

❯ env WEBPACK_REPORT=1 yarn webpack

this in the docs: http://dev.apollodata.com/core/fragments.html#unique-names
Error parsing bundle asset "/Users/vslobodin/Development/gitlab/gitlab-development-kit/gitlab/public/assets/webpack/sandboxed_mermaid.chunk.js": Identifier 'module' has already been declared (30689:6)

There is an issue in upsteam https://github.com/mermaid-js/mermaid/issues/3799

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