Configure NPM to save exact versions

[netweb]

In #43055 and ​#GB2512 an .npmrc file was added to /trunk to Gutenberg to save npm package versions as exact versions in the package.json file.

This should also be performed for the 5.0 branch, this will ensure everyone is using the same p[ackage versions

Exact versions are ensured by configuring a project-level .npmrc with save-exact = true.

Using exact versions helps avoid avoid and reduce debugging cost of bugs by guaranteeing that two installations of Gutenberg WordPress are running the same dependency versions. It is typically recommendable for applications, whereas a library may want to allow some flexibility in the dependencies it supports (assuming trust in SemVer).

Note: Due to the complexity of the commits in #43055 I'm creating this ticket instead of reopening that ticket

[netweb]

Patch 45149.diff​ details:

• There are 5 devDependencies versions that are bumped to the current latest which would match the previous semver constraint, under the assumption that this is what would currently be installed by a fresh clone anyways.

• There are only some optional (see below) changes to the package-lock.json file as the existing versions are already used in the package-lock.json file

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After applying the 45149.diff​ on my Mac and running npm install the package-lock.json changes are the inverse of the changes added in [43801]

These changes can be seen in the 45149-lock.diff​ file attached (do not commit this patch)

[youknowriad]

This needs to be updated and it doesn't feel very important for me for 5.0 RC. We have the package-lock.json. We can improve once ready.

[pento]

#45455 was marked as a duplicate.