[kbn/dev-utils] break up the mini monolith

[spalger]

We've run into issues with @kbn/dev-utils in the past, and they keep coming because we have so many different things in a single package. Some of those issues include massive cache invalidation whenever anything in that package changes, another is the need for special package.json files to be able to import sections of the dev-utils for things like @kbn/pm which don't want to embed all of that code into the dist. As we move to bazel we're got another issue that I'm not sure how to solve: types produced by that package won't link as expected after #95433 is merged.

I think it's time we break this package up into its separate pieces. We might want to support "domains" or whatever as described by #71566 as the packages directory is already growing pretty large, but this seems like the right path forward.

[elasticmachine]

Pinging @elastic/kibana-operations (Team:Operations)

[tylersmalley]

There is an opportunity here to experiment with using a folder hierarchy for this.