Inlines antlr4 package from upstream

[ncordon]

What

Inlines the antlr4 Javascript upstream package in the repository

Why

Because we contributed a performance improvement that has yet not made it into a usable release. This is intended to be temporary. We want for users not to find perfomance issues when they use the language support.

How

This has been done by doing:

git subtree split --prefix=runtime/JavaScript -b javascript
# To recover license on top of the tree in ANTLR repo
git checkout LICENSE.txt
git add . && git commit -m "Adds LICENSE of main ANTLR repo"

# Move everything into a subdirectory
mkdir -p packages/antlr4
mv * packages/antlr4
mv .babelrc .c8rc.json .eslintignore .eslintrc.yml .gitignore .project packages/antlr4

git add . && git commit -m "Moves everything inside packages/antlr4 folder"

and then inside this repo locally:

git remote add antlr4-local /Users/ncordon/neo4j/intellisense/antlr4
git merge antlr4-local/javascript --allow-unrelated-histories

[OskarDamkjaer]

let's hope we get a new release from antlr soon 🤞

[ncordon]

Let's leave the PR open for now and wait for an official release. At least it's easier to rebase changes instead of doing all the process of adding antlr4 and adjusting the build scripts etc again.

If they don't release a new antlr4 before our NODES conference, we can merge this the week before that.