Use @wessberg/rollup-plugin-ts + change output naming structure

[tunnckoCore]

Addresses #208 and #200.

• Switch the output naming structure/convention. We are kind of forced to do that to make a better and more predictable experience, and integrating this plugin.
• Update tsdx create according to new output structure; Plus, correct "package generation". Currently, if user type @hela/core in the prompt it will create core folder in the cwd and also will add to the generated package.json file a name field to be core instead @hela/core, which definitely isn't correct behavior.
• Remove the "utils safePackageName" test.
• Remove the safePackageName function, at all.
• ESLint autofix is enabled on my VSCode, so ESLint removed the use strict on the tsdx-build.test.js, obviously according to the given eslint config and prettier.
• Immediately before I started anything with just pnpm i on fresh branch, the pnpm's lockfile changed.

The only left is to update the babelPluginTsdx file, meaning to drop the rollup-plugin-babel dependency and just generate babel config and pass it as babelConfig option to the ts plugin. But keep in mind the ts plugin also automatically includes some plugins and does merging some default options.

[jaredpalmer]

Why are we changing the output format?

[jaredpalmer]

I would like to keep the dev/prod distinction in cjs. Also this is breaking change

[jaredpalmer]

If we were nice we would automagically update folks package.json for them

[tunnckoCore]

Meaning? Codemod thingy? It's could be the next possible step after this whole change.

[jaredpalmer]

I am confused. Is .min the production version?

[tunnckoCore]

Sure. Why otherwise one will want minifying? and especially, in cjs/node target.

[tunnckoCore]

Why are we changing the output format?

For "reasons", the other PR has comments around that :) Or at least because such design decisions, problems and "features" appear in some other places/tools (referring the new "hook" option in the ts plugin). All this is just one simple example that may seem negligible, but this is happening for years in the ecosystem.